Migrate spelling-0.0.21 changes from main

## Summary of the Pull Request

Currently, when the MRU is enabled we lose the keybinding allowing us to 
go forward/backward (aka right/left in LTR) in the tab view.

To fix that, this PR introduces "tabSwitcherMode" optional parameter to 
the prevTab / nextTab commands.
If it is not provided the global setting will be used.


So if you want to go to adjacent tabs, even if MRU is enabled on the
system level you can use:
```
{ "command": { "action": "prevTab", "tabSwitcherMode": "inOrder" }, "keys": "ctrl+f1"}
{ "command": { "action": "nextTab", "tabSwitcherMode": "inOrder" }, "keys": "ctrl+f2"}
```
or even
```
{"command": { "action": "prevTab", "tabSwitcherMode": "disabled" }, "keys": "ctrl+f1"}
{ "command": { "action": "nextTab", "tabSwitcherMode": "disabled" }, "keys": "ctrl+f2"}
```
if you don't want tab switcher to show up

<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist
* [x] Closes https://github.com/microsoft/terminal/issues/9330
* [x] CLA signed. 
* [x] Tests added/passed
* [ ] Documentation updated - not yet. Waiting for approval.
* [x] Schema updated.
* [ ] I've discussed this with core contributors already.

.github/ISSUE_TEMPLATE/Bug_Report.md

@@ -1,54 +0,0 @@
----
-name: "Bug report 🐛"
-about: Report errors or unexpected behavior
-title: ''
-labels: ''
-assignees: ''
-
----
-
-<!-- 
-🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨
-
-I ACKNOWLEDGE THE FOLLOWING BEFORE PROCEEDING:
-1. If I delete this entire template and go my own path, the core team may close my issue without further explanation or engagement.
-2. If I list multiple bugs/concerns in this one issue, the core team may close my issue without further explanation or engagement.
-3. If I write an issue that has many duplicates, the core team may close my issue without further explanation or engagement (and without necessarily spending time to find the exact duplicate ID number).
-4. If I leave the title incomplete when filing the issue, the core team may close my issue without further explanation or engagement.
-5. If I file something completely blank in the body, the core team may close my issue without further explanation or engagement.
-
-All good? Then proceed!
--->
-
-<!--
-This bug tracker is monitored by Windows Terminal development team and other technical folks.
-
-**Important: When reporting BSODs or security issues, DO NOT attach memory dumps, logs, or traces to Github issues**.
-Instead, send dumps/traces to secure@microsoft.com, referencing this GitHub issue.
-
-If this is an application crash, please also provide a Feedback Hub submission link so we can find your diagnostic data on the backend. Use the category "Apps > Windows Terminal (Preview)" and choose "Share My Feedback" after submission to get the link.
-
-Please use this form and describe your issue, concisely but precisely, with as much detail as possible.
-
--->
-
-# Environment
-
-```none
-Windows build number: [run `[Environment]::OSVersion` for powershell, or `ver` for cmd]
-Windows Terminal version (if applicable):
-
-Any other software?
-```
-
-# Steps to reproduce
-
-<!-- A description of how to trigger this bug. -->
-
-# Expected behavior
-
-<!-- A description of what you're expecting, possibly containing screenshots or reference material. -->
-
-# Actual behavior
-
-<!-- What's actually happening? -->

.github/ISSUE_TEMPLATE/Bug_Report.yml

@@ -0,0 +1,57 @@
+name: "Bug report 🐛"
+description: Report errors or unexpected behavior
+title: ''
+labels: ''
+assignees: ''
+issue_body: true
+body:
+- type: markdown
+  attributes:
+    value: |
+      Please make sure to [search for existing issues](https://github.com/microsoft/terminal/issues) before filing a new one!
+
+      If this is an application crash, please also provide a [Feedback Hub](https://aka.ms/terminal-feedback-hub) submission link so we can find your diagnostic data on the backend. Use the category "Apps > Windows Terminal" and choose "Share My Feedback" after submission to get the link.
+
+- type: input
+  attributes:
+    label: Windows Terminal version (or Windows build number)
+    placeholder: "10.0.19042.0, 1.7.3651.0"
+    description: |
+      If you are reporting an issue in Windows Terminal, you can find the version in the about dialog.
+
+      If you are reporting an issue with the Windows Console, please run `ver` or `[Environment]::OSVersion`.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Other Software
+    description: If you're reporting a bug about our interaction with other software, what software? What versions?
+    placeholder: |
+      vim 8.2 (inside WSL)
+      OpenSSH_for_Windows_8.1p1
+      My Cool Application v0.3 (include a code snippet if it would help!)
+  validations:
+    required: false
+
+- type: textarea
+  attributes:
+    label: Steps to reproduce
+    placeholder: Tell us the steps required to trigger your bug.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Expected Behavior
+    description: If you want to include screenshots, paste them into the markdown editor below the form or follow up with a separate comment.
+    placeholder: What were you expecting?
+  validations:
+    required: false
+
+- type: textarea
+  attributes:
+    label: Actual Behavior
+    placeholder: What happened instead?
+  validations:
+    required: true

.vscode/extensions.json

@@ -0,0 +1,13 @@
+{
+    // See https://go.microsoft.com/fwlink/?LinkId=827846 to learn about workspace recommendations.
+    // Extension identifier format: ${publisher}.${name}. Example: vscode.csharp
+
+    // List of extensions which should be recommended for users of this workspace.
+    "recommendations": [
+        "ms-vscode.cpptools"
+    ],
+    // List of extensions recommended by VS Code that should not be recommended for users of this workspace.
+    "unwantedRecommendations": [
+        
+    ]
+}

.vscode/launch.json

@@ -0,0 +1,24 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Debug OpenConsole by Launching (x64, debug)",
+            "type": "cppvsdbg",
+            "request": "launch",
+            "program": "${workspaceFolder}\\bin\\x64\\debug\\openconsole.exe",
+            "args": [],
+            "stopAtEntry": false,
+            "cwd": "${workspaceFolder}",
+            "environment": [],
+        },
+        {
+            "name": "Debug Terminal by Attaching (You go build/register/launch it first.)",
+            "type": "cppvsdbg",
+            "request": "attach",
+            "processId": "${command:pickProcess}"
+        }
+    ]
+}

.vscode/settings.json

@@ -0,0 +1,32 @@
+{
+    "C_Cpp.default.browse.databaseFilename": "${workspaceFolder}\\.vscode\\.BROWSE.VC.DB",
+    "C_Cpp.default.browse.path": [
+        "${workspaceFolder}"
+    ],
+    "C_Cpp.loggingLevel": "None",
+    "files.associations": {
+        "xstring": "cpp",
+        "*.idl": "cpp",
+        "array": "cpp",
+        "future": "cpp",
+        "istream": "cpp",
+        "memory": "cpp",
+        "tuple": "cpp",
+        "type_traits": "cpp",
+        "utility": "cpp",
+        "variant": "cpp",
+        "xlocmes": "cpp",
+        "xlocmon": "cpp",
+        "xlocnum": "cpp",
+        "xloctime": "cpp",
+        "multi_span": "cpp",
+        "pointers": "cpp",
+        "vector": "cpp"
+    },
+    "files.exclude": {
+        "**/bin/**": true,
+        "**/obj/**": true,
+        "**/packages/**": true,
+        "**/generated files/**": true
+    }
+}

.vscode/tasks.json

@@ -0,0 +1,107 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "type": "process",
+            "label": "Build Terminal/Console",
+            "command": "powershell.exe",
+            "args": [
+              "-Command",
+              "Import-Module ${workspaceFolder}\\tools\\OpenConsole.psm1;",
+              "Set-MsBuildDevEnvironment;",
+              "$project = switch(\"${input:buildProjectChoice}\"){OpenConsole{\"Conhost\\Host_EXE\"} Terminal{\"Terminal\\CascadiaPackage\"}};",
+              "$target = switch(\"${input:buildModeChoice}\"){Build{\"\"} Rebuild{\":Rebuild\"} Clean{\":Clean\"}};",
+              "$target = $project + $target;",
+              "msbuild",
+              "${workspaceFolder}\\OpenConsole.sln",
+              "/p:Configuration=${input:configChoice}",
+              "/p:Platform=${input:platformChoice}",
+              "/t:$target",
+              "/verbosity:minimal"
+            ],
+            "problemMatcher": ["$msCompile"],
+            "group": {
+              "kind": "build",
+              "isDefault": true
+            },
+            "runOptions": {
+                "reevaluateOnRerun": false,
+                "instanceLimit": 1,
+                "runOn": "default"
+            }
+        },
+        {
+            "type": "process",
+            "label": "Register Windows Terminal x64 Debug",
+            "command": "powershell.exe",
+            "args": [
+              "-Command",
+              "Import-Module ${workspaceFolder}\\tools\\OpenConsole.psm1;",
+              "Set-MsBuildDevEnvironment;",
+              "Set-Location -Path ${workspaceFolder}\\src\\cascadia\\CascadiaPackage\\AppPackages\\CascadiaPackage_0.0.1.0_x64_Debug_Test;",
+              "if ((Get-AppxPackage -Name 'WindowsTerminalDev*') -ne $null) { Remove-AppxPackage 'WindowsTerminalDev_0.0.1.0_x64__8wekyb3d8bbwe'};",
+              "New-Item ..\\loose -Type Directory -Force;",
+              "makeappx unpack /v /o /p .\\CascadiaPackage_0.0.1.0_x64_Debug.msix /d ..\\Loose\\;",
+              "Add-AppxPackage -Path ..\\loose\\AppxManifest.xml -Register -ForceUpdateFromAnyVersion -ForceApplicationShutdown"
+            ],
+            "problemMatcher": ["$msCompile"],
+            "group": {
+              "kind": "build",
+              "isDefault": true
+            }
+        },
+        {
+            "type": "process",
+            "label": "Run Windows Terminal Dev",
+            "command": "wtd.exe",
+            "args": [
+            ],
+            "problemMatcher": ["$msCompile"],
+        }
+    ],
+    "inputs":[
+        {
+            "id": "platformChoice",
+            "type": "pickString",
+            "description": "Processor architecture choice",
+            "options":[
+                "x64",
+                "x86",
+                "arm64"
+            ],
+            "default": "x64"
+        },
+        {
+            "id": "configChoice",
+            "type": "pickString",
+            "description": "Debug or release?",
+            "options":[
+                "Debug",
+                "Release"
+            ],
+            "default": "Debug"
+        },
+        {
+            "id": "buildModeChoice",
+            "type": "pickString",
+            "description": "Build, rebuild, or clean?",
+            "options":[
+                "Build",
+                "Rebuild",
+                "Clean"
+            ],
+            "default": "Build"
+        },
+        {
+            "id": "buildProjectChoice",
+            "type": "pickString",
+            "description": "OpenConsole or Terminal?",
+            "options":[
+                "OpenConsole",
+                "Terminal"
+            ],
+            "default": "Terminal"
+        }
+
+    ]
+}

NuGet.Config

@@ -1,24 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
     <packageSources>
-        <add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />
-        <!-- Add repositories here to the list of available repositories -->
-        
-        <!-- Dependencies that we must carry because they're not on public nuget feeds right now. -->
+        <clear />
+        <!-- Dependencies that we can turn on to force override for testing purposes before uploading. -->
         <!--<add key="Static Package Dependencies" value="dep\packages" />-->
-        
-        <!-- Use our own NuGet Feed -->
         <add key="TerminalDependencies" value="https://pkgs.dev.azure.com/ms/terminal/_packaging/TerminalDependencies/nuget/v3/index.json" />
-		
-		<!-- Temporarily? use the feeds from our friends in MUX for Helix test stuff -->
-		<add key="dotnetfeed" value="https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json" />
-        <add key="dnceng" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-eng/nuget/v3/index.json" />
-        <add key="MUX-Dependencies" value="https://pkgs.dev.azure.com/ms/microsoft-ui-xaml/_packaging/MUX-Dependencies/nuget/v3/index.json" />
-        
-        <!-- Internal NuGet feeds that may not be accessible outside Microsoft corporate network -->
-        <!--<add key="TAEF - internal" value="https://microsoft.pkgs.visualstudio.com/DefaultCollection/_packaging/Taef/nuget/v3/index.json" />
-        <add key="OpenConsole - Internal" value="https://microsoft.pkgs.visualstudio.com/_packaging/OpenConsole/nuget/v3/index.json" />-->
     </packageSources>
+    <disabledPackageSources>
+        <clear />
+    </disabledPackageSources>
     <config>
         <add key="repositorypath" value=".\packages" />
     </config>

README.md

@@ -33,10 +33,23 @@ This is our preferred method.
 
 #### Via GitHub
 
-For users who are unable to install Terminal from the Microsoft Store, Terminal
-builds can be manually downloaded from this repository's [Releases
+For users who are unable to install Windows Terminal from the Microsoft Store,
+released builds can be manually downloaded from this repository's [Releases
 page](https://github.com/microsoft/terminal/releases).
 
+Download the `Microsoft.WindowsTerminal_<versionNumber>.msixbundle` file from
+the **Assets** section. To install the app, you can simply double-click on the
+`.msixbundle` file, and the app installer should automatically run. If that
+fails for any reason, you can try the following command at a PowerShell prompt:
+
+```powershell
+# NOTE: If you are using PowerShell 7+, please run
+# Import-Module Appx -UseWindowsPowerShell
+# before using Add-AppxPackage.
+
+Add-AppxPackage Microsoft.WindowsTerminal_<versionNumber>.msixbundle
+```
+
 > 🔴 Note: If you install Terminal manually:
 >
 > * Terminal will not auto-update when new builds are released so you will need

build/scripts/Test-WindowsTerminalPackage.ps1

@@ -58,7 +58,7 @@ Try {
 
     ### Check the activatable class entries for a few DLLs we need.
     $inProcServers = $Manifest.Package.Extensions.Extension.InProcessServer.Path
-    $RequiredInProcServers = ("TerminalApp.dll", "TerminalControl.dll", "TerminalConnection.dll")
+    $RequiredInProcServers = ("TerminalApp.dll", "Microsoft.Terminal.Control.dll", "Microsoft.Terminal.Remoting.dll", "Microsoft.Terminal.Settings.Editor.dll", "Microsoft.Terminal.Settings.Model.dll", "TerminalConnection.dll")
 
     Write-Verbose "InProc Servers: $inProcServers"
 

consolegit2gitfilters.json

@@ -21,7 +21,8 @@
     "/res/terminal/",
     "/doc/specs/",
     "/doc/cascadia/",
-    "/doc/user-docs/"
+    "/doc/user-docs/",
+    "/src/tools/MonarchPeasantSample/",
   ],
   "SuffixFilters": [
     ".dbb",
@@ -38,5 +39,5 @@
     ".rec",
     ".err",
     ".xlsx"
-  ]    
+  ]
 }

custom.props

@@ -3,9 +3,9 @@
   <!-- This file is read by XES, which we use in our Release builds. -->
   <PropertyGroup Label="Version">
     <XesUseOneStoreVersioning>true</XesUseOneStoreVersioning>
-    <XesBaseYearForStoreVersion>2020</XesBaseYearForStoreVersion>
+    <XesBaseYearForStoreVersion>2021</XesBaseYearForStoreVersion>
     <VersionMajor>1</VersionMajor>
-    <VersionMinor>6</VersionMinor>
+    <VersionMinor>8</VersionMinor>
     <VersionInfoProductName>Windows Terminal</VersionInfoProductName>
   </PropertyGroup>
 </Project>

doc/AddASetting.md

@@ -11,7 +11,7 @@
         - Yes, the large majority of the `DEFINE_PROPERTYKEY` defs are the same, it's only the last byte of the guid that changes
 
 2. Add matching fields to Settings.hpp
-    - add getters, setters, the whole drill.
+    - Add getters, setters, the whole drill.
 
 3. Add to the propsheet
     - We need to add it to *reading and writing* the registry from the propsheet, and *reading* the link from the propsheet. Yes, that's weird, but the propsheet is smart enough to re-use ShortcutSerialization::s_SetLinkValues, but not smart enough to do the same with RegistrySerialization.

doc/TAEF.md

@@ -48,3 +48,17 @@ Invoke-OpenConsoleTests
 ```
 
 `Invoke-OpenConsoleTests` supports a number of options, which you can enumerate by running `Invoke-OpenConsoleTests -?`.
+
+
+### Debugging Tests
+
+If you want to debug a test, you can do so by using the TAEF /waitForDebugger flag, such as:
+
+	runut *Tests.dll /name:TextBufferTests::TestInsertCharacter /waitForDebugger
+
+Replace the test name with the one you want to debug.  Then, TAEF will begin executing the test and output something like this:
+
+	TAEF: Waiting for debugger - PID <some PID> @ IP <some IP address>
+
+You can then attach to that PID in your debugger of choice.  In Visual Studio, you can use Debug -> Attach To Process, or you could use WinDbg or whatever you want.
+Once the debugger attaches, the test will execute and your breakpoints will be hit.

doc/cascadia/AddASetting.md

@@ -0,0 +1,397 @@
+# Adding Settings to Windows Terminal
+
+Adding a setting to Windows Terminal is fairly straightforward. This guide serves as a reference on how to add a setting.
+
+## 1. Terminal Settings Model
+
+The Terminal Settings Model (`Microsoft.Terminal.Settings.Model`) is responsible for (de)serializing and exposing settings.
+
+### `GETSET_SETTING` macro
+
+The `GETSET_SETTING` macro can be used to implement inheritance for your new setting and store the setting in the settings model. It takes three parameters:
+- `type`: the type that the setting will be stored as
+- `name`: the name of the variable for storage
+- `defaultValue`: the value to use if the user does not define the setting anywhere
+
+### Adding a Profile setting
+
+This tutorial will add `CloseOnExitMode CloseOnExit` as a profile setting.
+
+1. In `Profile.h`, declare/define the setting:
+
+```c++
+GETSET_SETTING(CloseOnExitMode, CloseOnExit, CloseOnExitMode::Graceful)
+```
+
+2. In `Profile.idl`, expose the setting via WinRT:
+
+```c++
+Boolean HasCloseOnExit();
+void ClearCloseOnExit();
+CloseOnExitMode CloseOnExit;
+```
+
+3. In `Profile.cpp`, add (de)serialization and copy logic:
+
+```c++
+// Top of file:
+// - Add the serialization key
+static constexpr std::string_view CloseOnExitKey{ "closeOnExit" };
+
+// CopySettings() or Copy():
+// - The setting is exposed in the Settings UI
+profile->_CloseOnExit = source->_CloseOnExit;
+
+// LayerJson():
+// - get the value from the JSON
+JsonUtils::GetValueForKey(json, CloseOnExitKey, _CloseOnExit);
+
+// ToJson():
+// - write the value to the JSON
+JsonUtils::SetValueForKey(json, CloseOnExitKey, _CloseOnExit);
+```
+
+  - If the setting is not a primitive type, in `TerminalSettingsSerializationHelpers.h` add (de)serialization logic for the accepted values:
+
+```c++
+// For enum values...
+JSON_ENUM_MAPPER(::winrt::Microsoft::Terminal::Settings::Model::CloseOnExitMode)
+{
+    JSON_MAPPINGS(3) = {
+        pair_type{ "always", ValueType::Always },
+        pair_type{ "graceful", ValueType::Graceful },
+        pair_type{ "never", ValueType::Never },
+    };
+};
+
+// For enum flag values...
+JSON_FLAG_MAPPER(::winrt::Microsoft::Terminal::TerminalControl::CopyFormat)
+{
+    JSON_MAPPINGS(5) = {
+        pair_type{ "none", AllClear },
+        pair_type{ "html", ValueType::HTML },
+        pair_type{ "rtf", ValueType::RTF },
+        pair_type{ "all", AllSet },
+    };
+};
+
+// NOTE: This is also where you can add functionality for...
+// - overloaded type support (i.e. accept a bool and an enum)
+// - custom (de)serialization logic (i.e. coordinates)
+```
+
+### Adding a Global setting
+
+Follow the "adding a Profile setting" instructions above, but do it on the `GlobalAppSettings` files.
+
+### Adding an Action
+
+This tutorial will add the `openSettings` action.
+
+1. In `KeyMapping.idl`, declare the action:
+
+```c++
+// Add the action to ShortcutAction
+enum ShortcutAction
+{
+    OpenSettings
+}
+```
+
+2. In `ActionAndArgs.cpp`, add serialization logic:
+
+```c++
+// Top of file:
+// - Add the serialization key
+static constexpr std::string_view OpenSettingsKey{ "openSettings" };
+
+// ActionKeyNamesMap:
+// - map the new enum to the json key
+{ OpenSettingsKey, ShortcutAction::OpenSettings },
+```
+
+3. If the action should automatically generate a name when it appears in the Command Palette...
+```c++
+// In ActionAndArgs.cpp GenerateName() --> GeneratedActionNames
+{ ShortcutAction::OpenSettings, RS_(L"OpenSettingsCommandKey") },
+
+// In Resources.resw for Microsoft.Terminal.Settings.Model.Lib,
+// add the generated name
+// NOTE: Visual Studio presents the resw file as a table.
+//       If you choose to edit the file with a text editor,
+//       the code should look something like this...
+<data name="OpenSettingsCommandKey" xml:space="preserve">
+    <value>Open settings file</value>
+</data>
+```
+
+4. If the action supports arguments...
+  - In `ActionArgs.idl`, declare the arguments
+```c++
+[default_interface] runtimeclass OpenSettingsArgs : IActionArgs
+{
+    // this declares the "target" arg
+    SettingsTarget Target { get; };
+};
+```
+  - In `ActionArgs.h`, define the new runtime class
+```c++
+struct OpenSettingsArgs : public OpenSettingsArgsT<OpenSettingsArgs>
+{
+    OpenSettingsArgs() = default;
+
+    // adds a getter/setter for your argument, and defines the json key
+    GETSET_PROPERTY(SettingsTarget, Target, SettingsTarget::SettingsFile);
+    static constexpr std::string_view TargetKey{ "target" };
+
+    public:
+        hstring GenerateName() const;
+
+        bool Equals(const IActionArgs& other)
+        {
+            auto otherAsUs = other.try_as<OpenSettingsArgs>();
+            if (otherAsUs)
+            {
+                return otherAsUs->_Target == _Target;
+            }
+            return false;
+        };
+
+        static FromJsonResult FromJson(const Json::Value& json)
+        {
+            // LOAD BEARING: Not using make_self here _will_ break you in the future!
+            auto args = winrt::make_self<OpenSettingsArgs>();
+            JsonUtils::GetValueForKey(json, TargetKey, args->_Target);
+            return { *args, {} };
+        }
+
+        IActionArgs Copy() const
+        {
+            auto copy{ winrt::make_self<OpenSettingsArgs>() };
+            copy->_Target = _Target;
+            return *copy;
+        }
+};
+```
+  - In `ActionArgs.cpp`, define `GenerateName()`. This is used to automatically generate a name when it appears in the Command Palette.
+  - In `ActionAndArgs.cpp`, add serialization logic:
+
+```c++
+// ActionKeyNamesMap --> argParsers
+{ ShortcutAction::OpenSettings, OpenSettingsArgs::FromJson },
+```
+
+### Adding an Action Argument
+
+Follow step 3 from the "adding an Action" instructions above, but modify the relevant `ActionArgs` files.
+
+## 2. Setting Functionality
+
+Now that the Terminal Settings Model is updated, Windows Terminal can read and write to the settings file. This section covers how to add functionality to your newly created setting.
+
+### App-level settings
+
+App-level settings are settings that affect the frame of Windows Terminal. Generally, these tend to be global settings. The `TerminalApp` project is responsible for presenting the frame of Windows Terminal. A few files of interest include:
+- `TerminalPage`: XAML control responsible for the look and feel of Windows Terminal
+- `AppLogic`: WinRT class responsible for window-related issues (i.e. the titlebar, focus mode, etc...)
+
+Both have access to a `CascadiaSettings` object, for you to read the loaded setting and update Windows Terminal appropriately.
+
+### Terminal-level settings
+
+Terminal-level settings are settings that affect a shell session. Generally, these tend to be profile settings. The `TerminalApp` project is responsible for packaging this settings from the Terminal Settings Model to the terminal instance. There are two kinds of settings here:
+- `IControlSettings`:
+  - These are settings that affect the `TerminalControl` (a XAML control that hosts a shell session).
+  - Examples include background image customization, interactivity behavior (i.e. selection), acrylic and font customization.
+  - The `TerminalControl` project has access to these settings via a saved `IControlSettings` member.
+- `ICoreSettings`:
+  - These are settings that affect the `TerminalCore` (a lower level object that interacts with the text buffer).
+  - Examples include initial size, history size, and cursor customization.
+  - The `TerminalCore` project has access to these settings via a saved `ICoreSettings` member.
+
+`TerminalApp` packages these settings into a `TerminalSettings : IControlSettings, ICoreSettings` object upon creating a new terminal instance. To do so, you must submit the following changes:
+- Declare the setting in `IControlSettings.idl` or `ICoreSettings.idl` (whichever is relevant to your setting). If your setting is an enum setting, declare the enum here instead of in the `TerminalSettingsModel` project.
+- In `TerminalSettings.h`, declare/define the setting...
+```c++
+// The GETSET_PROPERTY macro declares/defines a getter setter for the setting.
+// Like GETSET_SETTING, it takes in a type, name, and defaultValue.
+GETSET_PROPERTY(bool, UseAcrylic, false);
+```
+- In `TerminalSettings.cpp`...
+  - update `_ApplyProfileSettings` for profile settings
+  - update `_ApplyGlobalSettings` for global settings
+  - If additional processing is necessary, that would happen here. For example, `backgroundImageAlignment` is stored as a `ConvergedAlignment` in the Terminal Settings Model, but converted into XAML's separate horizontal and vertical alignment enums for packaging.
+
+### Actions
+
+Actions are packaged as an `ActionAndArgs` object, then handled in `TerminalApp`. To add functionality for actions...
+- In the `ShortcutActionDispatch` files, dispatch an event when the action occurs...
+```c++
+// ShortcutActionDispatch.idl
+event Windows.Foundation.TypedEventHandler<ShortcutActionDispatch, Microsoft.Terminal.Settings.Model.ActionEventArgs> OpenSettings;
+
+// ShortcutActionDispatch.h
+TYPED_EVENT(OpenSettings, TerminalApp::ShortcutActionDispatch, Microsoft::Terminal::Settings::Model::ActionEventArgs);
+
+// ShortcutActionDispatch.cpp --> DoAction()
+// - dispatch the appropriate event
+case ShortcutAction::OpenSettings:
+{
+    _OpenSettingsHandlers(*this, eventArgs);
+    break;
+}
+```
+- In `TerminalPage` files, handle the event...
+```c++
+// TerminalPage.h
+// - declare the handler
+void _HandleOpenSettings(const IInspectable& sender, const Microsoft::Terminal::Settings::Model::ActionEventArgs& args);
+
+// TerminalPage.cpp --> _RegisterActionCallbacks()
+// - register the handler
+_actionDispatch->OpenSettings({ this, &TerminalPage::_HandleOpenSettings });
+
+// AppActionHandlers.cpp
+// - direct the function to the right place and call a helper function
+void TerminalPage::_HandleOpenSettings(const IInspectable& /*sender*/,
+                                       const ActionEventArgs& args)
+{
+    // NOTE: this if-statement can be omitted if the action does not support arguments
+    if (const auto& realArgs = args.ActionArgs().try_as<OpenSettingsArgs>())
+    {
+        _LaunchSettings(realArgs.Target());
+        args.Handled(true);
+    }
+}
+```
+
+`AppActionHandlers` vary based on the action you want to perform. A few useful helper functions include:
+- `_GetFocusedTab()`: retrieves the focused tab
+- `_GetActiveControl()`: retrieves the active terminal control
+- `_GetTerminalTabImpl()`: tries to cast the given tab as a `TerminalTab` (a tab that hosts a terminal instance)
+
+
+## 3. Settings UI
+
+### Exposing Enum Settings
+If the new setting supports enums, you need to expose a map of the enum and the respective value in the Terminal Settings Model's `EnumMappings`:
+
+```c++
+// EnumMappings.idl
+static Windows.Foundation.Collections.IMap<String, Microsoft.Terminal.Settings.Model.CloseOnExitMode> CloseOnExitMode { get; };
+
+// EnumMappings.h
+static winrt::Windows::Foundation::Collections::IMap<winrt::hstring, CloseOnExitMode> CloseOnExitMode();
+
+// EnumMappings.cpp
+// - this macro leverages the json enum mapper in TerminalSettingsSerializationHelper to expose
+//   the mapped values across project boundaries
+DEFINE_ENUM_MAP(Model::CloseOnExitMode, CloseOnExitMode);
+```
+
+### Binding and Localizing the Enum Setting
+
+Find the page in the Settings UI that the new setting fits best in. In this example, we are adding `LaunchMode`.
+1. In `Launch.idl`, expose the bindable setting...
+```c++
+// Expose the current value for the setting
+IInspectable CurrentLaunchMode;
+
+// Expose the list of possible values
+Windows.Foundation.Collections.IObservableVector<Microsoft.Terminal.Settings.Editor.EnumEntry> LaunchModeList { get; };
+```
+
+2. In `Launch.h`, declare the bindable enum setting...
+```c++
+// the GETSET_BINDABLE_ENUM_SETTING macro accepts...
+// - name: the name of the setting
+// - enumType: the type of the setting
+// - settingsModelName: how to retrieve the setting (use State() to get access to the settings model)
+// - settingNameInModel: the name of the setting in the terminal settings model
+GETSET_BINDABLE_ENUM_SETTING(LaunchMode, Model::LaunchMode, State().Settings().GlobalSettings, LaunchMode);
+```
+
+3. In `Launch.cpp`, populate these functions...
+```c++
+// Constructor (after InitializeComponent())
+// the INITIALIZE_BINDABLE_ENUM_SETTING macro accepts...
+// - name: the name of the setting
+// - enumMappingsName: the name from the TerminalSettingsModel's EnumMappings
+// - enumType: the type for the enum
+// - resourceSectionAndType: prefix for the localization
+// - resourceProperty: postfix for the localization
+INITIALIZE_BINDABLE_ENUM_SETTING(LaunchMode, LaunchMode, LaunchMode, L"Globals_LaunchMode", L"Content");
+```
+
+4. In `Resources.resw` for Microsoft.Terminal.Settings.Editor, add the localized text to expose each enum value. Use the following format: `<SettingGroup>_<SettingName><EnumValue>.Content`
+  - `SettingGroup`:
+    - `Globals` for global settings
+    - `Profile` for profile settings
+  - `SettingName`:
+    - the Pascal-case format for the setting type (i.e. `LaunchMode` for `"launchMode"`)
+  - `EnumValue`:
+    - the json key for the setting value, but with the first letter capitalized (i.e. `Focus` for `"focus"`)
+  - The resulting resw key should look something like this `Globals_LaunchModeFocus.Content`
+  - This is the text that will be used in your control
+
+### Updating the UI
+
+When adding a setting to the UI, make sure you follow the [UWP design guidance](https://docs.microsoft.com/windows/uwp/design/).
+
+#### Enum Settings
+
+Now, create a XAML control in the relevant XAML file. Use the following tips and tricks to style everything appropriately:
+- Wrap the control in a `ContentPresenter` adhering to the `SettingContainerStyle` style
+- Bind `SelectedItem` to the relevant `Current<Setting>` (i.e. `CurrentLaunchMode`). Ensure it's a TwoWay binding
+- Bind `ItemsSource` to `<Setting>List` (i.e. `LaunchModeList`)
+- Set the ItemTemplate to the `Enum<ControlType>Template` (i.e. `EnumRadioButtonTemplate` for radio buttons)
+- Set the style to the appropriate one in `CommonResources.xaml`
+
+```xml
+<!--Launch Mode-->
+<ContentPresenter Style="{StaticResource SettingContainerStyle}">
+    <muxc:RadioButtons x:Uid="Globals_LaunchMode"
+                       SelectedItem="{x:Bind CurrentLaunchMode, Mode="TwoWay"}"
+                       ItemsSource="{x:Bind LaunchModeList}"
+                       ItemTemplate="{StaticResource EnumRadioButtonTemplate}"
+                       Style="{StaticResource RadioButtonsSettingStyle}"/>
+</ContentPresenter>
+```
+
+To add any localized text, add a `x:Uid`, and access the relevant property via the Resources.resw file. For example, `Globals_LaunchMode.Header` sets the header for this control. You can also set the tooltip text like this:
+`Globals_DefaultProfile.[using:Windows.UI.Xaml.Controls]ToolTipService.ToolTip`.
+
+#### Non-Enum Settings
+
+Continue to reference `CommonResources.xaml` for appropriate styling and wrap the control with a similar `ContentPresenter`. However, instead of binding to the `Current<Setting>` and `<Setting>List`, bind directly to the setting via the state. Binding a setting like `altGrAliasing` should look something like this:
+```xml
+<!--AltGr Aliasing-->
+<ContentPresenter Style="{StaticResource SettingContainerStyle}">
+    <CheckBox x:Uid="Profile_AltGrAliasing"
+              IsChecked="{x:Bind State.Profile.AltGrAliasing, Mode=TwoWay}"
+              Style="{StaticResource CheckBoxSettingStyle}"/>
+</ContentPresenter>
+```
+
+#### Profile Settings
+
+If you are specifically adding a Profile setting, in addition to the steps above, you need to make the setting observable by modifying the `Profiles` files...
+```c++
+// Profiles.idl --> ProfileViewModel
+// - this declares the setting as observable using the type and the name of the setting
+OBSERVABLE_PROJECTED_SETTING(Microsoft.Terminal.Settings.Model.CloseOnExitMode, CloseOnExit);
+
+// Profiles.h --> ProfileViewModel
+// - this defines the setting as observable off of the _profile object
+OBSERVABLE_PROJECTED_SETTING(_profile, CloseOnExit);
+
+// Profiles.h --> ProfileViewModel
+// - if the setting cannot be inherited by another profile (aka missing the Clear() function), use the following macro instead:
+PERMANENT_OBSERVABLE_PROJECTED_SETTING(_profile, Guid);
+```
+
+The `ProfilePageNavigationState` holds a `ProfileViewModel`, which wraps the `Profile` object from the Terminal Settings Model. The `ProfileViewModel` makes all of the profile settings observable.
+
+### Actions
+
+Actions are not yet supported in the Settings UI.

doc/cascadia/profiles.schema.json

@@ -76,9 +76,11 @@
         "copy",
         "duplicateTab",
         "find",
+        "findMatch",
         "moveFocus",
         "moveTab",
         "newTab",
+        "newWindow",
         "nextTab",
         "openNewTabDropdown",
         "openSettings",
@@ -93,6 +95,8 @@
         "scrollDownPage",
         "scrollUp",
         "scrollUpPage",
+        "scrollToBottom",
+        "scrollToTop",
         "sendInput",
         "setColorScheme",
         "setTabColor",
@@ -103,6 +107,7 @@
         "toggleFocusMode",
         "toggleFullscreen",
         "togglePaneZoom",
+        "toggleReadOnlyMode",
         "toggleShaderEffects",
         "wt",
         "unbound"
@@ -135,6 +140,13 @@
       ],
       "type": "string"
     },
+    "FindMatchDirection": {
+      "enum": [
+        "next",
+        "prev"
+      ],
+      "type": "string"
+    },
     "SplitState": {
       "enum": [
         "vertical",
@@ -210,10 +222,28 @@
           "$ref": "#/definitions/Color",
           "default": null,
           "description": "If provided, will set the tab's color to the given value"
+        },
+        "suppressApplicationTitle": {
+          "type": "boolean",
+          "default": "false",
+          "description": "When set to true, tabTitle overrides the default title of the tab and any title change messages from the application will be suppressed. When set to false, tabTitle behaves as normal"
         }
       },
       "type": "object"
     },
+    "SwitchToAdjacentTabArgs" : {
+      "oneOf": [
+        { "type": "null" },
+        {
+          "enum": [
+            "mru",
+            "inOrder",
+            "disabled"
+          ],
+          "type": "string"
+        }
+      ]
+    },
     "ShortcutAction": {
       "properties": {
         "action": {
@@ -369,6 +399,13 @@
             "splitMode": {
               "default": "duplicate",
               "description": "Control how the pane splits. Only accepts \"duplicate\" which will duplicate the focused pane's profile into a new pane."
+            },
+            "size": {
+              "default": 0.5,
+              "description": "Specify how large the new pane should be, as a fraction of the current pane's size. 1.0 would be 'all of the current pane', and 0.0 is 'None of the parent'. Accepts floating point values from 0-1 (default 0.5).",
+              "maximum": 1,
+              "minimum": 0,
+              "type": "number"
             }
           }
         }
@@ -549,6 +586,67 @@
         }
       ]
     },
+    "FindMatchAction": {
+      "description": "Arguments corresponding to a Find Match Action",
+      "allOf": [
+        { "$ref": "#/definitions/ShortcutAction" },
+        {
+          "properties": {
+            "action": { "type": "string", "pattern": "findMatch" },
+            "direction": {
+              "$ref": "#/definitions/FindMatchDirection",
+              "default": "prev",
+              "description": "The direction to search in. \"prev\" will search upwards in the buffer, and \"next\" will search downwards."
+            }
+          }
+        }
+      ],
+      "required": [ "direction" ]
+    },
+    "NewWindowAction": {
+      "description": "Arguments corresponding to a New Window Action",
+      "allOf": [
+        { "$ref": "#/definitions/ShortcutAction" },
+        { "$ref": "#/definitions/NewTerminalArgs" },
+        {
+          "properties": {
+            "action": { "type":"string", "pattern": "newWindow" }
+          }
+        }
+      ]
+    },
+    "PrevTabAction": {
+      "description": "Arguments corresponding to a Previous Tab Action",
+      "allOf": [
+        { "$ref": "#/definitions/ShortcutAction" },
+        {
+          "properties": {
+            "action": { "type":"string", "pattern": "prevTab" },
+            "tabSwitcherMode": {
+              "$ref": "#/definitions/SwitchToAdjacentTabArgs",
+              "default": null,
+              "description": "Move to the previous tab using \"tabSwitcherMode\". If no mode is provided, use the one globally defined one."
+            }
+          }
+        }
+      ]
+    },
+    "NextTabAction": {
+      "description": "Arguments corresponding to a Next Tab Action",
+      "allOf": [
+        { "$ref": "#/definitions/ShortcutAction" },
+        {
+          "properties": {
+            "action": { "type":"string", "pattern": "nextTab" },
+            "tabSwitcherMode": {
+              "$ref": "#/definitions/SwitchToAdjacentTabArgs",
+              "default": null,
+              "description": "Move to the next tab using \"tabSwitcherMode\". If no mode is provided, use the one globally defined one."
+            }
+          }
+        }
+      ]
+    },
     "Keybinding": {
       "additionalProperties": false,
       "properties": {
@@ -573,6 +671,10 @@
               { "$ref": "#/definitions/ScrollUpAction" },
               { "$ref": "#/definitions/ScrollDownAction" },
               { "$ref": "#/definitions/MoveTabAction" },
+              { "$ref": "#/definitions/FindMatchAction" },
+              { "$ref": "#/definitions/NewWindowAction" },
+              { "$ref": "#/definitions/NextTabAction" },
+              { "$ref": "#/definitions/PrevTabAction" },
               { "type": "null" }
             ]
         },
@@ -620,11 +722,26 @@
           "description": "When set to true, tabs are always displayed. When set to false and \"showTabsInTitlebar\" is set to false, tabs only appear after opening a new tab.",
           "type": "boolean"
         },
+        "centerOnLaunch": {
+          "default": false,
+          "description": "When set to `true`, the terminal window will auto-center itself on the display it opens on. The terminal will use the \"initialPosition\" to determine which display to open on.",
+          "type": "boolean"
+        },
+        "inputServiceWarning": {
+          "default": true,
+          "description": "Warning if 'Touch Keyboard and Handwriting Panel Service' is disabled.",
+          "type": "boolean"
+        },
         "copyOnSelect": {
           "default": false,
           "description": "When set to true, a selection is immediately copied to your clipboard upon creation. When set to false, the selection persists and awaits further action.",
           "type": "boolean"
         },
+        "focusFollowMouse": {
+          "default": false,
+          "description": "When set to true, the terminal will focus the pane on mouse hover.",
+          "type": "boolean"
+        },
         "copyFormatting": {
           "default": true,
           "description": "When set to `true`, the color and font formatting of selected text is also copied to your clipboard. When set to `false`, only plain text is copied to your clipboard. An array of specific formats can also be used. Supported array values include `html` and `rtf`. Plain text is always copied.",
@@ -649,6 +766,10 @@
           "description": "Sets the default profile. Opens by clicking the \"+\" icon or typing the key binding assigned to \"newTab\".",
           "type": "string"
         },
+        "startupActions": {
+          "description": "Sets the list of actions to apply if no command line is provided. Uses the same format as command line arguments",
+          "type": "string"
+        },
         "disabledProfileSources": {
           "description": "Disables all the dynamic profile generators in this list, preventing them from adding their profiles to the list of profiles on startup.",
           "items": {
@@ -793,6 +914,16 @@
               "type": "string"
             }
           ]
+        },
+        "windowingBehavior": {
+          "default": "useNew",
+          "description": "Controls how new terminal instances attach to existing windows. \"useNew\" will always create a new window. \"useExisting\" will create new tabs in the most recently used window on this virtual desktop, and \"useAnyExisting\" will create tabs in the most recent window on any desktop.",
+          "enum": [
+            "useNew",
+            "useExisting",
+            "useAnyExisting"
+          ],
+          "type": "string"
         }
       },
       "required": [
@@ -914,17 +1045,18 @@
           "description": "Sets the color of the cursor. Overrides the cursor color from the color scheme. Uses hex color format: \"#rrggbb\"."
         },
         "cursorHeight": {
-          "description": "Sets the percentage height of the cursor starting from the bottom. Only works when cursorShape is set to \"vintage\". Accepts values from 25-100.",
+          "description": "Sets the percentage height of the cursor starting from the bottom. Only works when cursorShape is set to \"vintage\". Accepts values from 1-100.",
           "maximum": 100,
-          "minimum": 25,
+          "minimum": 1,
           "type": ["integer","null"],
           "default": 25
         },
         "cursorShape": {
           "default": "bar",
-          "description": "Sets the shape of the cursor. Possible values:\n -\"bar\" ( ┃, default )\n -\"emptyBox\" ( ▯ )\n -\"filledBox\" ( █ )\n -\"underscore\" ( ▁ )\n -\"vintage\" ( ▃ )",
+          "description": "Sets the shape of the cursor. Possible values:\n -\"bar\" ( ┃, default )\n -\"doubleUnderscore\" ( ‗ )\n -\"emptyBox\" ( ▯ )\n -\"filledBox\" ( █ )\n -\"underscore\" ( ▁ )\n -\"vintage\" ( ▃ )",
           "enum": [
             "bar",
+            "doubleUnderscore",
             "emptyBox",
             "filledBox",
             "underscore",

doc/specs/#2871 - Pane Navigation/#2871 - Pane Navigation.md

@@ -0,0 +1,302 @@
+---
+author: Mike Griese @zadjii-msft
+created on: 2020-11-23
+last updated: 2020-12-15
+issue id: #2871
+---
+
+# Focus Pane Actions
+
+## Abstract
+
+Currently, the Terminal only allows users to navigate through panes
+_directionally_. However, we might also want to allow a user to navigate through
+panes in most recently used order ("MRU" order), or to navigate directly to a
+specific pane. This spec proposes some additional actions in order to enable
+these sorts of scenarios.
+
+## Background
+
+### Inspiration
+
+`tmux` allows the user to navigate through panes using its `select-pane`
+command. The `select-pane` command works in the following way:
+
+```
+select-pane [-DLlMmRU] [-T title] [-t target-pane]
+
+     Make pane target-pane the active pane in window target-window, or set its
+     style (with -P).  If one of -D, -L, -R, or -U is used, respectively the
+     pane below, to the left, to the right, or above the target pane is used.
+     -l is the same as using the last-pane command.
+
+     -m and -M are used to set and clear the marked pane.  There is one marked
+     pane at a time, setting a new marked pane clears the last.  The marked pane
+     is the default target for -s to join-pane, swap-pane and swap-window.
+```
+_from `man tmux`_.
+
+The Terminal currently allows the user to navigate through panes with the
+`moveFocus` action, which only accepts a `direction` to move in.
+
+Additionally, the Terminal allows movement between tabs with the `nextTab` and
+`prevTab` actions, who move between tabs either in-order or in MRU order.
+Furthermore, these actions may or may not display the "tab switcher" user
+interface, based on the value of `tabSwitcherMode`.
+
+### User Stories
+
+* **Scenario 1**: A user who wants to be able to split the window into 4 equal
+  corners from the commandline. Currently this isn't possible, because the user
+  cannot move focus during the startup actions - `split-pane` actions always end
+  up splitting the current leaf in the tree of panes. (see [#5464])
+* **Scenario 2**: A user who wants to quickly navigate to the previous pane they
+  had opened. (see [#2871])
+* **Scenario 3**: A user who wants to bind a keybinding like <kbd>alt+1</kbd>,
+  <kbd>alt+2</kbd>, etc to immediately focus the first, second, etc. pane in a
+  tab. (see [#5803])
+
+### Future Considerations
+
+There's been talk of updating the advanced tab switcher to also display panes,
+in addition to just tabs. This would allow users to navigate through the ATS
+directly to a pane, and see all the panes in a tab. Currently, `tabSwitcherMode`
+changes the behavior of `nextTab`, `prevTab` - should we just build the
+`paneSwitcherMode` directly into the action we end up designing?
+
+## Solution Design
+
+Does using the pane switcher with a theoretical `focusPane(target=id)` action
+even make sense? Certainly not! That's like `switchToTab(index=id)`, the user
+already knows which tab they want to go to, there's no reason to pop an
+ephemeral UI in front of them.
+
+Similarly, it almost certainly doesn't make sense to display the pane switcher
+while moving focus directionally. Consider moving focus with a key bound to the
+arrow keys. Displaying another UI in front of them while moving focus with the
+arrow keys would be confusing.
+
+Addressing Scenario 1 is relatively easy. So long as we add any of the proposed
+actions, including the existing `moveFocus` action as a subcommand that can be
+passed to `wt.exe`, then the user should be able to navigate through the panes
+they've created with the startup commandline, and build the tree of panes
+however they see fit.
+
+Scenario 2 is more complicated, because MRU switching is always more
+complicated. Without a UI of some sort, there's no way to switch to another pane
+in the MRU order without also updating the MRU order as you go. So this would
+almost certainly necessitate a "pane switcher", like the tab switcher.
+
+
+### Proposal A: Add next, prev to moveFocus
+
+* `moveFocus(direction="up|down|left|right|next|prev")`
+
+* **Pros**:
+  - Definitely gets the "MRU Pane Switching" scenario working
+* **Cons**:
+  - Doesn't really address any of the other scenarios
+  - How will it play with pane switching in the UI?
+  - MRU switching without a dialog to track & display the MRU stack doesn't
+    really work - this only allows to the user to navigate to the most recently
+    used pane, or through all the panes in least-recently-used order. This is
+    because switching to the MRU pane _will update the MRU pane_.
+
+❌ This proposal is no longer being considered.
+
+### Proposal B: focusNextPane, focusPrevPane with order, useSwitcher args
+
+```json
+// Focus pane 1
+// - This is sensible, no arguments here
+{ "command": { "action": "focusPane", "id": 1 } },
+
+// Focus the next MRU pane
+// - Without the switcher, this can only go one pane deep in the MRU stack
+// - presumably once there's a pane switcher, it would default to enabled?
+{ "command": { "action": "focusNextPane", "order": "mru" } },
+
+// Focus the prev inOrder pane
+// - this seems straightforward
+{ "command": { "action": "focusPrevPane", "order": "inOrder" } },
+
+// Focus the next pane, in mru order, explicitly disable the switcher
+// - The user opted in to only being able to MRU switch one deep. That's fine, that's what they want.
+{ "command": { "action": "focusNextPane", "order": "mru", "useSwitcher": false} },
+
+// Focus the prev inOrder pane, explicitly with the switcher
+// - Maybe they disabled the switcher globally, but what it on for this action?
+{ "command": { "action": "focusPrevPane", "order": "inOrder", "useSwitcher": true } },
+```
+_From [discussion in the implementation
+PR](https://github.com/microsoft/terminal/pull/8183#issuecomment-729672645)_
+
+Boiled down, that's three actions:
+* `focusPane(target=id)`
+* `focusNextPane(order="inOrder|mru", useSwitcher=true|false)`
+* `focusPrevPane(order="inOrder|mru", useSwitcher=true|false)`
+
+* **Pros**:
+  - Everything is explicit, including the option to use the pane switcher (when
+    available)
+  - Adds support for in-order pane switching
+  - No "conditional parameters" - where providing one argument makes other
+    arguments invalid or ambiguous.
+* **Cons**:
+  - Doesn't really address any of the other scenarios
+  - What does the "next most-recently-used tab" even mean? How is it different
+    than "previous most-recently-used tab"? Semantically, these are the same
+    thing!
+  - No one's even asked for in-order pane switching. Is that a UX that even
+    really makes sense?
+
+❌ This proposal is no longer being considered.
+
+> 👉 **NOTE**: At this point, we stopped considering navigating in both MRU
+> "directions", since both the next and prev MRU pane are the same thing. We're
+> now using "last" to mean "the previous MRU pane".
+
+### Proposal C: One actions, combine the args
+
+* `moveFocus(target=id|"up|down|left|right|last")`
+
+* **Pros**:
+  - Absolutely the least complicated action to author. There's only one
+    parameter, `target`.
+  - No "conditional parameters".
+* **Cons**:
+  - How do we express this in the Settings UI? Mixed-type enums work fine for
+    the font weight, where each enum value has a distinct integer value it maps
+    to, but in this case, using `id` is entirely different from the other
+    directional values
+
+❌ This proposal is no longer being considered.
+
+### Proposal D: Two actions
+
+* `focusPane(target=id)`
+* `moveFocus(direction="up|down|left|right|last")`
+
+* **Pros**:
+  - Each action does explicitly one thing.
+* **Cons**:
+  - two actions for _similar_ behavior
+  - This now forks the "Direction" enum into "MoveFocusDirection" and
+    "ResizeDirection" (because `resizePane(last)` doesn't make any sense).
+
+This proposal doesn't really have any special consideration for the pane
+switcher UX. Neither of these actions would summon the pane switcher UX.
+
+### Proposal E: Three actions
+
+* `focusPane(target=id)`
+* `moveFocus(direction="up|down|left|right")`
+* `focusLastPane(usePaneSwitcher=false|true)`
+
+In this design, neither `focusPane` nor `moveFocus` will summon the pane
+switcher UI (even once it's added). However, the `focusLastPane` one _could_,
+and subsequent keypresses could pop you through the MRU stack, while it's
+visible? The pane switcher could then display the panes for the tab in MRU
+order, and the user could just use the arrow keys to navigate the list if they
+so choose.
+
+* **Pros**:
+  - Each action does explicitly one thing.
+  - Design accounts for future pane switcher UX
+* **Cons**:
+  - Three separate actions for similar behavior
+
+❌ This proposal is no longer being considered.
+
+### Proposal F: It's literally just tmux
+
+_Also known as the "one action to rule them all" proposal_
+
+`focusPane(target=id, direction="up|down|left|right|last")`
+
+Previously, this design was avoided, because what does `focusPane(target=4,
+direction=down)` do? Does it focus pane 4, or does it move focus down?
+
+`tmux` solves this in one action by just doing both!
+
+```
+Make pane target-pane the active pane ...  If one of -D, -L, -R, or -U is used,
+respectively the pane below, to the left, to the right, or above the target pane
+is used.
+```
+_from `man tmux`_.
+
+So `focusPane(target=1, direction=up)` will attempt to focus the pane above pane
+1. This action would not summon the pane switcher UX, even for
+`focusPane(direction=last)`
+
+* **Pros**:
+  - Fewest redundant actions
+* **Cons**:
+  - Is this intuitive? That combining the params would do both, with `target`
+    happening "first"?
+  - Assumes that there will be a separate action added in the future for "Open
+    the pane switcher (with some given ordering)"
+
+
+> 👉 **NOTE**: At this point, the author considered "Do we even want a separate
+> action to engage the tab switcher with panes expanded?" Perhaps panes being
+> visible in the tab switcher is just part fo the tab switcher's behavior. Maybe
+> there shouldn't be a separate "open the tab switcher with the panes expanded
+> to the pane I'm currently on, and the panes listed in MRU order" action.
+
+❌ This proposal is no longer being considered.
+
+## Conclusion
+
+After much discussion as a team, we decided that **Proposal D** would be the
+best option. We felt that there wasn't a need to add any extra configuration to
+invoke the "pane switcher" as anything different than the "tab switcher". The
+"pane switcher" should really just exist as a part of the functionality of the
+advanced tab switcher, not as it's own thing.
+
+Additionally, we concurred that the new "direction" value should be `prev`, not
+`last`, for consistency's sake.
+
+## UI/UX Design
+
+The only real UX being added with the agreed upon design is allowing the user to
+execute an action to move to the previously active pane within a single tab. No
+additional UX (including the pane switcher) is being prescribed in this spec at
+this time.
+
+## Potential Issues
+
+<table>
+<tr>
+<td><strong>Compatibility</strong></td>
+<td>
+
+We've only adding a single enum value to an existing enum. Since we're not
+changing the meaning of any of the existing values, we do not expect any
+compatibility issues there. Additionally, we're not changing the default value
+of the `direction` param of the `moveFocus` action, so there are no further
+compatibility concerns there. Furthermore, no additional parameters are being
+added to the `moveFocus` action that would potentially give it a different
+meaning.
+
+</td>
+</tr>
+</table>
+
+In the current design, there's no way to move through all the panes with a
+single keybinding. For example, if a user wanted to bind <kbd>Alt+]</kbd> to
+move to the "next" pane, and <kbd>Alt+[</kbd> to move to the "previous" one.
+These movements would necessarily need to be in-order traversals, since there's
+no way of doing multiple MRU steps.
+
+Fortunately, no one's really asked for traversing the panes in-order, so we're
+not really worried about this. Otherwise, it would maybe make sense for `last`
+to be the "previous MRU pane", and reserve `next`/`prev` for in-order traversal.
+
+
+[#2871]: https://github.com/microsoft/terminal/issues/2871
+[#5464]: https://github.com/microsoft/terminal/issues/5464
+[#5803]: https://github.com/microsoft/terminal/issues/5803
+
+

doc/specs/#3062 - Appearance configuration object for profiles.md

@@ -0,0 +1,128 @@
+---
+author: Pankaj Bhojwani, pabhojwa@microsoft.com
+created on: 2020-11-20
+last updated: 2021-2-5
+issue id: #8345
+---
+
+# Appearance configuration objects for profiles
+
+## Abstract
+
+This spec outlines how we can support 'configuration objects' in our profiles, which
+will allow us to render differently depending on the state of the control. For example, a
+control can be rendered differently if it's focused as compared to when it's unfocused.
+
+## Inspiration
+
+Reference: [#3062](https://github.com/microsoft/terminal/issues/3062)
+
+Users want there to be a more visible indicator than the one we have currently for which
+pane is focused and which panes are unfocused. This change would grant us that feature.
+
+## Solution Design
+
+The implementation design for appearance config objects centers around the recent change where inheritance was added to the
+`TerminalSettings` class in the Terminal Settings Model - i.e. different `TerminalSettings` objects can inherit from each other.
+The reason for this change was that we did not want a settings reload to erase any overrides `TermControl` may have made
+to the settings during runtime. By instead passing a child of the `TerminalSettings` object to the control, we can change
+the parent of the child during a settings reload without the overrides being erased (since those overrides live in the child).
+
+The idea behind unfocused appearance configurations is similar. We will pass in another `TerminalSettings` object to the control,
+which is simply a child that already has some overrides in it. When the control gains or loses focus, it simply switches between
+the two settings objects appropriately.
+
+### Allowed parameters
+
+For now, these states are meant to be entirely appearance-based. So, not all parameters which can be
+defined in a `Profile` can be defined in this new object (for example, we do not want parameters which
+would cause a resize in this object.) Here is the list of parameters we will allow:
+
+- Anything regarding colors: `colorScheme`, `foreground`, `background`, `cursorColor` etc
+- Anything regarding background image: `path`, `opacity`, `alignment`, `stretchMode`
+- `cursorShape`
+
+We may wish to allow further parameters in these objects in the future (like `bellStyle`?). The addition
+of further parameters can be discussed in the future and is out of scope for this spec.
+
+### Inheritance
+
+The inheritance model can be thought of as an 'all-or-nothing' approach in the sense that the `unfocusedAppearance` object
+is considered as a *single* setting instead of an object with many settings. We have chosen this model because it is cleaner
+and easier to understand than the alternative, where each setting within an `unfocusedAppearance` object has a parent from which
+it obtains its value.
+
+Note that when `TerminalApp` initializes a control, it creates a `TerminalSettings` object for that profile and passes the
+control a child of that object (so that the control can store overrides in the child, as described earlier). If an unfocused
+config is defined in the profile (or in globals/profile defaults), then `TerminalApp` will create a *child of that child*,
+put the relevant overrides in it, and pass that into the control as well. Thus, the inheritance of any undefined parameters
+in the unfocused config will be as follows:
+
+1. The unfocused config specified in the profile (or in globals/profile defaults)
+2. Overrides made by the terminal control
+3. The parent profile
+
+## UI/UX Design
+
+Users will be able to add a new setting to their profiles that will look like this:
+
+```
+"unfocusedAppearance":
+{
+    "colorScheme": "Campbell",
+    "cursorColor": "#888",
+    "cursorShape": "emptyBox",
+    "foreground": "#C0C0C0",
+    "background": "#000000"
+}
+```
+
+When certain appearance settings are changed via OSC sequences (such as the background color), only the focused/regular
+appearance will change and the unfocused one will remain unchanged. However, since the unfocused settings object inherits
+from the regular one, it will still apply the change (provided it does not define its own value for that setting).
+
+## Capabilities
+
+### Accessibility
+
+Does not affect accessibility.
+
+### Security
+
+Does not affect security.
+
+### Reliability
+
+This is another location in the settings where parsing/loading the settings may fail. However, this is the case
+for any new setting we add so I would say that this is a reasonable cost for this feature.
+
+### Compatibility
+
+Should not affect compatibility.
+
+### Performance, Power, and Efficiency
+
+Rapidly switching between many panes, causing several successive appearance changes in a short period of time, could
+potentially impact performance. However, regular/reasonable pane switching should not have a noticeable effect.
+
+## Potential Issues
+
+Inactive tabs will be 'rendered' in the background with the `UnfocusedRenderingParams` object, we need to make
+sure that switching to an inactive tab (and so causing the renderer to update with the 'normal' parameters)
+does not cause the window to flash/show a jarring indicator that the rendering values changed.
+
+## Future considerations
+
+We will need to decide how this will look in the settings UI.
+
+We may wish to add more states in the future (like 'elevated'). When that happens, we will need to deal with how
+these appearance objects can scale/layer over each other. We had a lot of discussion about this and could not find
+a suitable solution to the problem of multiple states being valid at the same time (like unfocused and elevated).
+This, along with the fact that it is uncertain if there even will be more states we would want to add led us to
+the conclusion that we should only support the unfocused state for now, and come back to this issue later. If there
+are no more states other than unfocused and elevated, we could allow combining them (like having an 'unfocused elevated' state).
+If there are more states, we could do the implementation as an extension rather than inherently supporting it.
+
+## Resources
+
+

doc/specs/#5000 - Process Model 2.0/#4472 - Windows Terminal Session Management.md

@@ -0,0 +1,562 @@
+---
+author: Mike Griese @zadjii-msft
+created on: 2020-10-30
+last updated: 2020-02-05
+issue id: #4472
+---
+
+# Windows Terminal Session Management
+
+## Abstract
+This document is intended to serve as an addition to the [Process Model 2.0
+Spec]. That document provides a big-picture overview of changes to the entirety
+of the Windows Terminal process architecture, including both the split of
+window/content processes, as well as the introduction of monarch/peasant
+processes. The focus of that document was to identify solutions to a set of
+scenarios that were closely intertwined, and establish these solutions would
+work together, without preventing any one scenario from working. What that
+document did not do was prescribe specific solutions to the given scenarios.
+
+This document offers a deeper dive on a subset of the issues in [#5000], to
+describe specifics for managing multiple windows with the Windows Terminal. This
+includes features such as:
+
+* Run `wt` in the current window ([#4472])
+* Single Instance Mode ([#2227])
+
+## Solution Design
+
+### Monarch and Peasant Processes
+
+This document assumes the reader is already familiar with the "Monarch and
+Peasant" architecture as detailed in the [Windows Terminal Process Model 2.0
+Spec]. As a quick summary:
+
+* Every Windows Terminal window is a "Peasant" process.
+* One of the Windows Terminal window processes is also the "Monarch" process.
+  The Monarch is picked randomly from the Terminal windows, and there is only
+  ever one Monarch process at a time.
+* Peasants can communicate with the monarch when certain state changes (such as
+  their window being activated), and the monarch can send commands to any of the
+  peasants.
+
+This architecture will be used to enable each of the following scenarios.
+
+### Scenario: Open new tabs in most recently used window
+
+A common feature of many browsers is that when a web URL is clicked somewhere,
+the web page is opened as a new tab in the most recently used window of the
+browser. This functionality is often referred to as "glomming", as the new tab
+"gloms" onto the existing window.
+
+Currently, the terminal does not support such a feature - every `wt` invocation
+creates a new window. With the monarch/peasant architecture, it'll now be
+possible to enable such a scenario.
+
+As each window is activated, it will call a method on the `Monarch` object
+(hosted by the monarch process) which will indicate that "I am peasant N, and
+I've been focused". The monarch will use those method calls to update its own
+internal stack of the most recently used windows.
+
+Whenever a new `wt.exe` process is launched, that process will _first_ ask the
+monarch if it should run the commandline in an existing window, or create its
+own window.
+
+![auto-glom-wt-exe](auto-glom-wt-exe.png)
+
+If glomming is enabled, the monarch will dispatch the commandline to the
+appropriate window for them to handle instead. To the user, it'll seem as if the
+tab just opened in the most recent window.
+
+Users should certainly be able to specify if they want new instances to glom
+onto the MRU window or not. You could imagine that currently, we default to the
+hypothetical value `"windowingBehavior": "useNew"`, meaning that each new wt gets
+its own new window.
+
+If glomming is disabled, then the Monarch will call back to the peasant and tell
+it to run the provided commandline. The monarch will use the return value of
+`ExecuteCommandline` to indicate that the calling process should create a window
+and become a peasant process, and run the commandline itself.
+
+#### Glomming within the same virtual desktop
+
+When links are opened in the new Edge browser, they will only glom onto an
+existing window if that window is open in the current virtual desktop. This
+seems like a good idea of a feature for the Terminal to follow as well.
+
+There must be some way for an application to determine which virtual desktop it
+is open on. We could use that information to have the monarch track the last
+active window _per-desktop_, and only glom when there's one on the current
+desktop.
+
+We could make the `windowingBehavior` property accept a variety of
+configurations:
+
+- `"useExisting"`: always glom to the most recent window, regardless of desktop.
+- `"useExistingOnSameDesktop"`: Only glom if there's an existing window on this
+  virtual desktop, otherwise create a new window. This will be the new default
+  value.
+- `"useNew"`: Never glom, always create a new window. This is technically the
+  current behavior of the Terminal.
+
+### Handling the current working directory
+
+Consider the following scenario: the user runs `wt -d .` in the address bar of
+explorer, and the monarch determines that this new tab should be created in an
+existing window. For clarity during this example, we will label the existing
+window WT[1], and the second `wt.exe` process WT[2].
+
+An example of this scenario is given in the following diagram:
+
+![single-instance-mode-cwd](single-instance-mode-cwd.png)
+
+In this scenario, we want the new tab to be spawned in the current working
+directory of WT[2], not WT[1]. So when WT[1] is about to run the commands that
+were passed to WT[2], WT[1] will need to:
+
+* First, stash its own CWD
+* Change to the CWD of WT[2]
+* Run the commands from WT[2]
+* Then return to its original CWD.
+
+So, as a part of the interface that a peasant uses to communicate the startup
+commandline to the monarch, we should also include the current working
+directory.
+
+### Scenario: Run `wt` in the current window
+
+One often requested scenario is the ability to run a `wt.exe` commandline in the
+current window, as opposed to always creating a new window. Presume we have the
+ability to communicate between different window processes. The logical extension
+of this scenario would be "run a `wt` commandline in _any_ given WT window".
+
+Each window process will have its own unique ID assigned to it by the monarch.
+This ID will be a positive number. Windows can also have names assigned to them.
+These names are strings that the user specifies. A window will always have an
+ID, but not necessarily a name. Running a command in a given window with ID N
+should be as easy as something like:
+
+```sh
+wt.exe --window N new-tab ; split-pane
+```
+
+(or for shorthand, `wt -w N new-tab ; split-pane`).
+
+More formally, we will add the following parameter to the top-level `wt`
+command:
+
+#### `--window,-w <window-id>`
+Run these commands in the given Windows Terminal session. This enables opening
+new tabs, splits, etc. in already running Windows Terminal windows.
+* If `window-id` is `0`, run the given commands in _the current window_.
+* If `window-id` is a negative number, or the reserved name `new`, run the
+  commands in a _new_ Terminal window.
+* If `window-id` is the ID or name of an existing window, then run the
+  commandline in that window.
+* If `window-id` is _not_ the ID or name of an existing window, create a new
+  window. That window will be assigned the ID or name provided in the
+  commandline. The provided subcommands will be run in that new window.
+* If `window-id` is omitted, then obey the value of `windowingBehavior` when
+  determining which window to run the command in.
+
+_Whenever_ `wt.exe` is started, it must _always_ pass the provided commandline
+first to the monarch process for handling. This is important for glomming
+scenarios (as noted above). The monarch will parse the commandline, determine
+which window the commandline is destined for, then call `ExecuteCommandline` on
+that peasant, who will then run the command.
+
+#### Running commands in the current window:`wt --window 0`
+
+If `wt -w 0 <commands>` is run _outside_ a WT instance, it could attempt to glom
+onto _the most recent WT window_ instead. This seems more logical than something
+like `wt --window last` or some other special value indicating "run this in the
+MRU window".<sup>[[2]](#footnote-2)</sup>
+
+That might be a simple, but **wrong**, implementation for "the current window".
+If the peasants always raise an event when their window is focused, and the
+monarch keeps track of the MRU order for peasants, then one could naively assume
+that the execution of `wt -w 0 <commands>` would always return the window the
+user was typing in, the current one. However, if someone were to do something
+like `sleep 10 ; wt -w 0 <commands>`, then the user could easily focus another
+WT window during the sleep, which would cause the MRU window to not be the same
+as the window executing the command.
+
+To solve this issue, we'll  other than
+attempting to use the `WT_SESSION` environment variable. If a `wt.exe` process
+is spawned and that's in its environment variables, it could try and ask the
+monarch for the peasant who's hosting the session corresponding to that GUID.
+This is more of a theoretical solution than anything else.
+
+In the past we've been reluctant to rely too heavily on `WT_SESSION`. However,
+an environment variable does seem to be the only reliable way to be confident
+where the window was created from. We could introduce another environment
+variable instead - `WT_WINDOW_ID`. That would allow us to shortcut the session
+ID lookup. However, I worry about exposing the window ID as an environment
+variable. If we do that, users will inevitably use that instead of the `wt -0`
+alias, which should take care of the work for them. Additionally, `WT_WINDOW_ID`
+wouldn't update in the child processes as tabs are torn out of windows to create
+new windows.
+
+Both solutions are prone to the user changing the value of the variable to some
+garbage value. If they do that, this lookup will most certainly not work as
+expected. Using the session ID (a GUID) instead of the window ID (an int) makes
+it less likely that they guess the ID of an existing instance.
+
+#### Running commands in a new window:`wt --window -1` / `wt --window new`
+
+If the user passes a negative number, or the reserved name `new` to the
+`--window` parameter, then we will always create a new window for that
+commandline, regardless of the value of `windowingBehavior`. This will allow
+users to do something like `wt -w -1 new-tab` to _always_ create a new window.
+
+#### `--window` in subcommands
+
+The `--window` parameter is a setting to `wt.exe` itself, not to one of its
+subcommands (like `new-tab` or `split-pane`). This means that all of the
+subcommands in a particular `wt` commandline will all be handled by the same
+session. For example, let us consider a user who wants to open a new tab in
+window 2, and split a new pane in window 3, all at once. The user _cannot_ do
+something like:
+
+```cmd
+wt -w 2 new-tab ; -w 3 split-pane
+```
+
+Instead, the user will need to separate the commands (by whatever their shell's
+own command delimiter is) and run two different `wt.exe` instances:
+
+```cmd
+wt -w 2 new-tab & wt -w 3 split-pane
+```
+
+This is done to make the parsing of the subcommands easier, and for the internal
+passing of arguments simpler. If the `--window` parameter were a part of each
+subcommand, then each individual subcommand's parser would need to be
+enlightened about that parameter, and then it would need to be possible for any
+single part of the commandline to call out to another process. It would be
+especially tricky then to coordinate the work being done across process here.
+The source process would need some sort of way to wait for the other process to
+notify the source that a particular subcommand completed, before allowing the
+source to dispatch the next part of the commandline.
+
+Overall, this is seen as unnecessarily complex, and dispatching whole sets of
+commands as a simpler solution.
+
+### Naming Windows
+
+It's not user-friendly to rely on automatically generated, invisible numbers to
+identify windows. There's not a great way of identifying which window is which.
+The user would need to track the IDs in their head manually. Instead, we'll
+allow the user to provide a string name for the window. This name can be used to
+address a window in addition to the ID.
+
+Names can be provided on the commandline, in the original commandline. For
+example, `wt -w foo nt` would name the new window "foo". Names can also be set
+with a new action, `NameWindow`<sup>[[3]](#footnote-3)</sup>. `name-window`
+could also be used as a subcommand. For example, `wt -w 4 name-window bar` would
+name window 4 "bar".
+
+To keep identities mentally distinct, we will disallow names that are integers
+(positive or negative). This will prevent users from renaming a window to `2`,
+then having `wt -w 2` be ambiguous as to which window it refers to.
+
+Names must also be unique. If a user attempts to set the name of the window to
+an already-used name, we'll need to ignore the name change. We could also
+display a "toast" or some other type of low-impact message to the user. That
+message would have some text like: "Unable to rename window. Another window with
+that name already exists".
+
+The Terminal will reserve the name `new`. It will also reserve any names
+starting with the character `_`. The user will not be allowed to set the window
+name to any of these reserved names. Reserving `_*` allows us to add other
+keywords in the future, without introducing a breaking change.
+
+## UI/UX Design
+
+### `windowingBehavior` details
+
+The following list gives greater breakdown of the values of `windowingBehavior`,
+and how they operate:
+
+* `"windowingBehavior": "useExisting", "useExistingOnSameDesktop"`:
+  **Browser-like glomming**
+  - New instances open in the current window by default.
+  - `newWindow` opens a new window.
+  - Tabs can be torn out to create new windows.
+  - `wt -w -1` opens a new window.
+* `"windowingBehavior": "useNew"`: No auto-glomming. This is **the current
+  behavior** of the Terminal.
+  - New instances open in new windows by default
+  - `newWindow` opens a new window
+  - Tabs can be torn out to create new windows.
+  - `wt -w -1` opens a new window.
+
+We'll be changing the default behavior from `useNew` to
+`useExistingOnSameDesktop`. This will be more consistent with other tabbed
+applications.
+
+## Concerns
+
+<table>
+<tr>
+<td><strong>Accessibility</strong></td>
+<td>
+
+There is no expected accessibility impact from this feature. Each window will
+handle UIA access as it normally does.
+
+In the future, we could consider exposing the window IDs and/or names via UIA.
+
+</td>
+</tr>
+<tr>
+<td><strong>Security</strong></td>
+<td>
+
+Many security concerns have already be covered in greater detail in the parent
+spec, [Process Model 2.0 Spec].
+
+When attempting to instantiate the Monarch, COM will only return the object from
+a server running at the same elevation level. We don't need to worry about
+unelevated peasants connecting to the elevated Monarch, or vice-versa.
+
+</td>
+</tr>
+<tr>
+<td><strong>Reliability</strong></td>
+<td>
+
+We will need to be careful when working with objects hosted by another process.
+Any work we do with it MUST be in a try/catch, because at _any_ time, the other
+process could be killed. At any point, a window process could be killed. Both
+the monarch and peasant code will need to be redundant to such a scenario, and
+if the other process is killed, make sure to display an appropriate error and
+either recover or exit gracefully.
+
+In any and all these situations, we will want to try and be as verbose as
+possible in the logging. This will make tracking which process had the error
+occur easier.
+
+</td>
+</tr>
+<tr>
+<td><strong>Compatibility</strong></td>
+<td>
+
+We will be changing the default behavior of the Terminal to auto-glom to the
+most-recently used window on the same desktop in the course of this work, which
+will be a breaking UX change. This is behavior that can be reverted with the
+`"windowingBehavior": "useNew"` setting.
+
+We acknowledge that this is a pretty massive change to the default experience of
+the Terminal. We're planning on doing some polling of users to determine which
+behavior they want by default. Additionally, we'll be staging the rollout of
+this feature, using the Preview builds of the Terminal. The release notes that
+first include it will call extra attention to this feature. We'll ask that users
+provide their feedback in a dedicated thread, so we have time to collect
+opinions from users before rolling the change out to all users.
+
+We may choose to only change the default to `useExistingOnSameDesktop` once tab
+tear out is available, so users who are particularly unhappy about this change
+can still tear out the tab (if they can't be bothered to change the setting).
+
+</td>
+</tr>
+<tr>
+<td><strong>Performance, Power, and Efficiency</strong></td>
+<td>
+
+There's no dramatic change expected here. There may be a minor delay in the
+spawning of new terminal instances, due to requiring cross-process hops for the
+communication between monarch and peasant processes.
+
+</td>
+</tr>
+</table>
+
+## Potential Issues
+
+### Mixed Elevation Levels
+
+As of December 2020, we're no longer pursuing a "mixed-elevation" scenario for
+the Terminal. This makes many of the cross-elevation scenarios simpler. Elevated
+and unelevated `wt` instances will always remain separate. The different
+elevation levels will maintain separate lists of window IDs. If the user is
+running both an elevated and unelevated window, then there will be two monarchs.
+One elevated, and the other unelevated.
+
+There will also be some edge cases when handling the commandline that will need
+special care. Say the user wanted to open a new tab in the elevated window, from
+and unelevated `explorer.exe`. That would be a commandline like:
+
+```sh
+wt -w 0 new-tab -d . --elevated
+```
+
+Typically we first determine which window the commandline is intended for, then
+dispatch it to that window. In this case, the `-w 0` will cause us to pass the
+commandline to the current unelevated window. Then, that window will try to open
+an elevated tab, fail, and create a new `wt.exe` process. This second `wt.exe`
+process will lose the `-w 0` context. It won't inform the elevated monarch that
+this commandline should be run in the active session.
+
+We will need to make sure that special care is taken when creating elevated
+instances that we maintain the `--window` parameter passed to the Terminal.
+
+### `wt` Startup Commandline Options
+
+There are a few commandline options which can be provided to `wt.exe` which
+don't make sense to pass to another session. These options include (but are not
+limited to):
+
+* `--initialSize r,c`
+* `--initialPosition x,y`
+* `--fullscreen`, `--maximized`, etc.
+
+When we're passing a commandline to another instance to handle, these arguments
+will be ignored. they only apply to the initial creation of a window.
+`--initialSize 32, 120` doesn't make sense if the window already has a size.
+
+On startup of a new window, we currently assume that the first command is always
+`new-tab`. When passing commandlines to existing windows, we won't need to make
+that assumption anymore. There will already be existing tabs.
+
+### Monarch MRU Window Tracking
+
+As stated above, the monarch is responsible for tracking the MRU window stack.
+However, when the monarch is closed, this state will be lost. The new monarch
+will be elected, but it will be unable to ask the old monarch for the MRU
+order of the windows.
+
+We had previously considered an _acceptable_ UX when this would occur. We would
+randomize the order (with the new monarch becoming the MRU window). If someone
+noticed this bug and complained, then we had a theoretical solution prepared.
+The peasants could inform not only the monarch, but _all other peasants_ when
+they become activated. This would mean all peasants are simultaneously tracking
+the MRU stack. This would mean that any given peasant would be prepared always
+to become the monarch.
+
+A simpler solution though would be to not track the MRU stack in the Monarch at
+all. Instead, each peasant could just track internally when they were last
+activated. The Monarch wouldn't track any state itself. It would be distributed
+across all the peasants. The Monarch could then iterate over the list of
+peasants and find the one with the newest `LastActivated` timestamp.
+
+Now, when a Monarch dies, the new Peasant doesn't have to come up with the stack
+itself. All the other Peasants keep their state. The new Monarch can query them
+and get the same answer the old Monarch would have.
+
+We could further optimize this by having the Monarch also track the stack. Then,
+the monarch could query the MRU window quickly. The `LastActivated` timestamps
+would only be used by a new Monarch when it is elected, to reconstruct the MRU
+stack.
+
+## Implementation Plan
+
+This is a list of actionable tasks generated as described by this spec:
+
+* [ ] Add support for `wt.exe` processes to be Monarchs and Peasants, and
+  communicate that state between themselves. This task does not otherwise add
+  any user-facing features, merely an architectural update.
+* [ ] Add support for the `windowingBehavior` setting as a boolean. Opening new
+  WT windows will conditionally glom to existing windows.
+* [ ] Add support for per-desktop `windowingBehavior`, by adding the support for
+  the enum values `"useExisting"`, `"useExistingOnSameDesktop"` and `"useNew"`.
+* [ ] Add support for `wt.exe` to pass commandlines intended for another window
+  to the monarch, then to the intended window, with the `--window,-w
+  window-id` commandline parameter.
+* [ ] Add support for targeting and naming windows via the `-w` parameter on the
+  commandline
+* [ ] Add a `NameWindow` action, subcommand that allows the user to set the name
+  for the window.
+* [ ] Add an action that will cause all windows to briefly display a overlay
+  with the current window ID and name. This would be something like the
+  "identify" feature of the Windows "Display" settings.
+
+## Future considerations
+
+* What if the user wanted to pipe a command to a pane in an existing window?
+  ```sh
+  man ping > wt -w 0 split-pane cat
+  ```
+  Is there some way for WT to pass its stdin/out handles to the child process
+  it's creating? This is _not_ related to the current spec at hand, just
+  something the author considered while writing the spec. This likely belongs
+  over in [#492], or in its own spec.
+  - Or I suppose, with less confusion, someone could run `wt -w 0 split-pane --
+    man ping > cat`. That's certainly more sensible, and wouldn't require any
+    extra work.
+* "Single Instance Mode" is a scenario in which there is only ever one single WT
+  window. A user might want this functionality to only ever allow a single
+  terminal window to be open on their desktop. This is especially frequently
+  requested in combination with "quake mode", as discussed in [#653]. When Single
+  Instance Mode is active, and the user runs a new `wt.exe` commandline, it will
+  always end up running in the existing window, if there is one.
+
+  An earlier version of this spec proposed a new value of `glomToLastWindow`.
+  (`glomToLastWindow` was later renamed `windowingBehavior`). The `always` value
+  would disable tab tear out<sup>[[1]](#footnote-1)</sup>. It would additionally
+  disable the `newWindow` action, and prevent `wt -w new` from opening a new
+  window.
+
+  In discussion, it was concluded that this setting didn't make sense. Why did the
+  `glomToLastWindow` setting change the behavior of tear out? Single Instance Mode
+  is most frequently requested in regards to quake mode. We're leaving the
+  implementation of true single instance mode to that spec.
+* It was suggested in review that we could auto-generate names for windows, from
+  some list of words. Prior art could be the URLS for gfycat.com or
+  what3words.com, which use three random words. I believe `docker` also assigns
+  names from a random selection of `adjective`+`name`. This is an interesting
+  idea, and something that could be pursued in the future.
+    - This would be a massive pain to localize though, hence why this is left as
+      a future consideration.
+* We will _need_ to provide a commandline tool to list windows and their IDs &
+  names. We're thinking a list of windows, their IDs, names, PIDs, and the title
+  of the window.
+
+  Currently we're stuck with `wt.exe` which is a GUI application, and cannot
+  print to the console. Our need is now fairly high for the ability to print
+  info to the console. To remedy this, we'll need to ship another helper exe as
+  a commandline tool for working with the terminal. The design for this is left
+  for the future.
+
+## Footnotes
+
+<a name="footnote-1"><a>[1]: While tear-out is a separate track of work from
+session management in general, this setting could be implemented along with this
+set of features, and later used to control tear out as well.
+
+<a name="footnote-2"><a>[2]: Since we're reserving the keyword `new` to mean "a
+new window", then we could also reserve `last` or `current` as an alias for "the
+current window".
+
+<a name="footnote-3"><a>[3]: We currently have two actions for renaming _tabs_
+in the Terminal: `renameTab(name)`, and `openTabRenamer()`. We will likely
+similarly need `nameWindow(name)` and `openWindowNamer()`. `openWindowNamer`
+could display a dialog to allow the user to rename the current window at
+runtime.
+
+
+## Resources
+
+* [Tab Tear-out in the community toolkit] - this document proved invaluable to
+  the background of tearing a tab out of an application to create a new window.
+
+<!-- Footnotes -->
+
+[#5000]: https://github.com/microsoft/terminal/issues/5000
+[#1256]: https://github.com/microsoft/terminal/issues/1256
+[#4472]: https://github.com/microsoft/terminal/issues/4472
+[#2227]: https://github.com/microsoft/terminal/issues/2227
+[#653]: https://github.com/microsoft/terminal/issues/653
+[#1032]: https://github.com/microsoft/terminal/issues/1032
+[#632]: https://github.com/microsoft/terminal/issues/632
+[#492]: https://github.com/microsoft/terminal/issues/492
+[#4000]: https://github.com/microsoft/terminal/issues/4000
+[#7972]: https://github.com/microsoft/terminal/pull/7972
+[#961]: https://github.com/microsoft/terminal/issues/961
+[`30b8335`]: https://github.com/microsoft/terminal/commit/30b833547928d6dcbf88d49df0dbd5b3f6a7c879
+[Tab Tear-out in the community toolkit]: https://github.com/windows-toolkit/Sample-TabView-TearOff
+[Quake mode scenarios]: https://github.com/microsoft/terminal/issues/653#issuecomment-661370107
+[`ISwapChainPanelNative2::SetSwapChainHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/windows.ui.xaml.media.dxinterop/nf-windows-ui-xaml-media-dxinterop-iswapchainpanelnative2-setswapchainhandle
+[Process Model 2.0 Spec]: https://github.com/microsoft/terminal/blob/main/doc/specs/%235000%20-%20Process%20Model%202.0/%235000%20-%20Process%20Model%202.0.md

doc/specs/#597 - Tab Sizing.md

@@ -0,0 +1,95 @@
+---
+author: Kayla Cinnamon @cinnamon-msft
+created on: 2020-01-03
+last updated: 2020-01-03
+issue id: 597
+---
+
+# Tab Sizing
+
+## Abstract
+
+This spec outlines the tab sizing feature. This is an application-level feature that is not profile-specific (at least for now).
+
+Global properties that encompass tab sizing:
+
+* `tabWidthMode` (accepts pre-defined values for tab sizing behavior)
+* `tabWidthMin` (can never be smaller than the icon width)
+* `tabWidthMax` (can never be wider than the tab bar)
+
+Acceptable values for `tabWidthMode`:
+
+* [default] `equal` (all tabs are sized the same, regardless of tab title length)
+* `titleLength` (width of tab contains entire tab title)
+
+## Inspiration
+
+Other browsers and terminals have varying tab width behavior, so we should give people options.
+
+## Solution Design
+
+`tabWidthMode` will be a global setting that will accept the following strings:
+
+* `equal`
+    * All tabs are equal in width
+    * If the tab bar has filled, tabs will shrink as additional tabs are added
+    * Utilizes the `equal` setting from WinUI's TabView
+
+* `titleLength`
+    * Tab width varies depending on title length
+    * Width of tab will fit the whole tab title
+    * Utilizes the `sizeToContent` setting from WinUI's TabView
+
+In addition to `tabWidthMode`, the following global properties will also be available:
+
+* `tabWidthMin`
+    * Accepts an integer
+    * Value correlates to the minimum amount of pixels the tab width can be
+    * If value is less than the width of the icon, the minimum width will be the width of the icon
+    * If value is greater than the width of the tab bar, the maximum width will be the width of the tab bar
+    * If not set, the tab will have the system-defined minimum width
+
+* `tabWidthMax`
+    * Accepts an integer
+    * Value correlates to the maximum amount of pixels the tab width can be
+    * If value is less than the width of the icon, the minimum width will be the width of the icon
+    * If value is greater than the width of the tab bar, the maximum width will be the width of the tab bar
+    * If not set, the tab will have the system-defined maximum width
+
+If `tabWidthMode` is set to `titleLength`, the tab widths will fall between the `tabWidthMin` and `tabWidthMax` values if they are set, depending on the length of the tab title.
+
+If `tabWidthMode` isn't set, the default experience will be `equal`. Justification for the default experience is the results from this [twitter poll](https://twitter.com/cinnamon_msft/status/1203093459055210496).
+
+## UI/UX Design
+
+[This tweet](https://twitter.com/cinnamon_msft/status/1203094776117022720) displays how the `equal` and `titleLength` values behave for the `tabWidthMode` property.
+
+## Capabilities
+
+### Accessibility
+
+This feature could impact accessibility if the tab title isn't stored within the metadata of the tab. If the tab width is the width of the icon, then the title isn't visible. The tab title will have to be accessible by a screen reader.
+
+### Security
+
+This feature will not impact security.
+
+### Reliability
+
+This feature will not impact reliability. It provides users with additional customization options.
+
+### Compatibility
+
+This feature will not break existing compatibility.
+
+### Performance, Power, and Efficiency
+
+## Potential Issues
+
+This feature will not impact performance, power, nor efficiency.
+
+## Future considerations
+
+* Provide tab sizing options per-profile
+* A `tabWidthMode` value that will evenly divide the entirety of the tab bar by the number of open tabs
+    * i.e. One tab will take the full width of the tab bar, two tabs will each take up half the width of the tab bar, etc.

doc/terminal-v2-roadmap.md

@@ -2,17 +2,16 @@
 
 ## Overview
 
-This document outlines the roadmap towards delivering Windows Terminal 2.0 by Spring 2021.
-
+This document outlines the roadmap towards delivering Windows Terminal 2.0 by Winter 2021.
 
 ## Milestones
 
-The Windows Terminal project is engineered and delivered as a set of 4-week milestones. New features will go into [Windows Terminal Preview](https://aka.ms/terminal-preview) first, then a month after they've been in Preview, those features will move into [Windows Terminal](https://aka.ms/terminal).
+Windows Terminal is engineered and delivered as a set of 6-week milestones. New features will go into [Windows Terminal Preview](https://aka.ms/terminal-preview) first, then a month after they've been in Preview, those features will move into [Windows Terminal](https://aka.ms/terminal).
 
 | Duration | Activity | Releases |
 | --- | --- | --- |
-| 2 weeks | Dev Work<br/> <ul><li>Fixes / Features for future Windows Releases</li><li>Fixes / Features for Windows Terminal</li></ul> |  Release to Internal Selfhosters at end of week 2 |
-| 1 week | Quality & Stability<br/> <ul><li>Bug Fixes</li><li>Perf & Stability</li><li>UI Polish</li><li>Tests</li><li>etc.</li></ul>| Push to Microsoft Store at end of week 3 |
+| 4 weeks | Dev Work<br/> <ul><li>Fixes / Features for future Windows Releases</li><li>Fixes / Features for Windows Terminal</li></ul> |  Release to Internal Selfhosters at end of week 4 |
+| 1 week | Quality & Stability<br/> <ul><li>Bug Fixes</li><li>Perf & Stability</li><li>UI Polish</li><li>Tests</li><li>etc.</li></ul>| Push to Microsoft Store at end of week 5 |
 | 1 week | Release <br/> <ul><li>Available from [Microsoft Store](https://aka.ms/terminal) & [GitHub Releases](https://github.com/microsoft/terminal/releases)</li><li>Release Notes & Announcement Blog published</li><li>Engineering System Maintenance</li><li>Community Engagement</li><li>Docs</li><li>Future Milestone Planning</li></ul> | Release available from Microsoft Store & GitHub Releases |
 
 ## Terminal Roadmap / Timeline
@@ -26,12 +25,15 @@ Below is the schedule for when milestones will be included in release builds of
 | 2020-08-31 | [1.3] in Windows Terminal Preview<br>[1.2] in Windows Terminal | [Windows Terminal Preview 1.3 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-3-release/) |
 | 2020-09-30 | [1.4] in Windows Terminal Preview<br>[1.3] in Windows Terminal | [Windows Terminal Preview 1.4 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-4-release/) |
 | 2020-11-30 | [1.5] in Windows Terminal Preview<br>[1.4] in Windows Terminal | [Windows Terminal Preview 1.5 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-5-release/) |
-| 2020-12-31 | [1.6] in Windows Terminal Preview<br>[1.5] in Windows Terminal | |
-| 2021-01-31 | 1.7 in Windows Terminal Preview<br>[1.6] in Windows Terminal | |
-| 2021-02-28 | 1.8 in Windows Terminal Preview<br>1.8 in Windows Terminal | |
-| 2021-03-31 | 1.9 in Windows Terminal Preview<br>1.9 in Windows Terminal | |
-| 2021-04-30 | 2.0 RC in Windows Terminal Preview<br>2.0 RC in Windows Terminal | |
-| 2021-05-31 | [2.0] in Windows Terminal Preview<br>[2.0] in Windows Terminal | |
+| 2021-01-31 | [1.6] in Windows Terminal Preview<br>[1.5] in Windows Terminal | [Windows Terminal Preview 1.6 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-6-release/) |
+| 2021-03-01 | [1.7] in Windows Terminal Preview<br>[1.6] in Windows Terminal | [Windows Terminal Preview 1.7 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-7-release/) |
+| 2021-04-30 | [1.8] in Windows Terminal Preview<br>[1.7] in Windows Terminal | |
+| 2021-05-31 | [1.9] in Windows Terminal Preview<br>[1.8] in Windows Terminal | |
+| 2021-07-31 | 1.10 in Windows Terminal Preview<br>[1.9] in Windows Terminal | |
+| 2021-08-30 | 1.11 in Windows Terminal Preview<br>1.10 in Windows Terminal | |
+| 2021-10-31 | 1.12 in Windows Terminal Preview<br>1.11 in Windows Terminal | |
+| 2021-11-30 | 2.0 RC in Windows Terminal Preview<br>2.0 RC in Windows Terminal | |
+| 2021-12-31 | [2.0] in Windows Terminal Preview<br>[2.0] in Windows Terminal | |
 
 ## Issue Triage & Prioritization
 
@@ -84,6 +86,9 @@ Feature Notes:
 [1.4]: https://github.com/microsoft/terminal/milestone/28
 [1.5]: https://github.com/microsoft/terminal/milestone/30
 [1.6]: https://github.com/microsoft/terminal/milestone/31
+[1.7]: https://github.com/microsoft/terminal/milestone/32
+[1.8]: https://github.com/microsoft/terminal/milestone/33
+[1.9]: https://github.com/microsoft/terminal/milestone/34
 [2.0]: https://github.com/microsoft/terminal/milestone/22
 [#1564]: https://github.com/microsoft/terminal/issues/1564
 [#6720]: https://github.com/microsoft/terminal/pull/6720

oss/fmt/cgmanifest.json

@@ -4,7 +4,7 @@
        "type": "git", 
        "git": { 
          "repositoryUrl": "https://github.com/fmtlib/fmt", 
-         "commitHash": "f19b1a521ee8b606dedcadfda69fd10ddf882753" 
+         "commitHash": "7bdf0628b1276379886c7f6dda2cef2b3b374f0b" 
          }
        }
     }

oss/fmt/include/fmt/chrono.h

@@ -72,43 +72,27 @@ FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
   static_assert(F::is_integer, "From must be integral");
   static_assert(T::is_integer, "To must be integral");
 
-  if (F::is_signed && !T::is_signed) {
+  if (detail::const_check(F::is_signed && !T::is_signed)) {
     // From may be negative, not allowed!
     if (fmt::detail::is_negative(from)) {
       ec = 1;
       return {};
     }
-
     // From is positive. Can it always fit in To?
-    if (F::digits <= T::digits) {
-      // yes, From always fits in To.
-    } else {
-      // from may not fit in To, we have to do a dynamic check
-      if (from > static_cast<From>((T::max)())) {
-        ec = 1;
-        return {};
-      }
+    if (F::digits > T::digits &&
+        from > static_cast<From>(detail::max_value<To>())) {
+      ec = 1;
+      return {};
     }
   }
 
-  if (!F::is_signed && T::is_signed) {
-    // can from be held in To?
-    if (F::digits < T::digits) {
-      // yes, From always fits in To.
-    } else {
-      // from may not fit in To, we have to do a dynamic check
-      if (from > static_cast<From>((T::max)())) {
-        // outside range.
-        ec = 1;
-        return {};
-      }
-    }
+  if (!F::is_signed && T::is_signed && F::digits >= T::digits &&
+      from > static_cast<From>(detail::max_value<To>())) {
+    ec = 1;
+    return {};
   }
-
-  // reaching here means all is ok for lossless conversion.
-  return static_cast<To>(from);
-
-}  // function
+  return static_cast<To>(from);  // Lossless conversion.
+}
 
 template <typename To, typename From,
           FMT_ENABLE_IF(std::is_same<From, To>::value)>
@@ -190,11 +174,9 @@ To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
   // safe conversion to IntermediateRep
   IntermediateRep count =
       lossless_integral_conversion<IntermediateRep>(from.count(), ec);
-  if (ec) {
-    return {};
-  }
+  if (ec) return {};
   // multiply with Factor::num without overflow or underflow
-  if (Factor::num != 1) {
+  if (detail::const_check(Factor::num != 1)) {
     const auto max1 = detail::max_value<IntermediateRep>() / Factor::num;
     if (count > max1) {
       ec = 1;
@@ -209,17 +191,9 @@ To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
     count *= Factor::num;
   }
 
-  // this can't go wrong, right? den>0 is checked earlier.
-  if (Factor::den != 1) {
-    count /= Factor::den;
-  }
-  // convert to the to type, safely
-  using ToRep = typename To::rep;
-  const ToRep tocount = lossless_integral_conversion<ToRep>(count, ec);
-  if (ec) {
-    return {};
-  }
-  return To{tocount};
+  if (detail::const_check(Factor::den != 1)) count /= Factor::den;
+  auto tocount = lossless_integral_conversion<typename To::rep>(count, ec);
+  return ec ? To() : To(tocount);
 }
 
 /**
@@ -351,6 +325,11 @@ inline std::tm localtime(std::time_t time) {
   return lt.tm_;
 }
 
+inline std::tm localtime(
+    std::chrono::time_point<std::chrono::system_clock> time_point) {
+  return localtime(std::chrono::system_clock::to_time_t(time_point));
+}
+
 // Thread-safe replacement for std::gmtime
 inline std::tm gmtime(std::time_t time) {
   struct dispatcher {
@@ -387,6 +366,11 @@ inline std::tm gmtime(std::time_t time) {
   return gt.tm_;
 }
 
+inline std::tm gmtime(
+    std::chrono::time_point<std::chrono::system_clock> time_point) {
+  return gmtime(std::chrono::system_clock::to_time_t(time_point));
+}
+
 namespace detail {
 inline size_t strftime(char* str, size_t count, const char* format,
                        const std::tm* time) {
@@ -399,6 +383,17 @@ inline size_t strftime(wchar_t* str, size_t count, const wchar_t* format,
 }
 }  // namespace detail
 
+template <typename Char>
+struct formatter<std::chrono::time_point<std::chrono::system_clock>, Char>
+    : formatter<std::tm, Char> {
+  template <typename FormatContext>
+  auto format(std::chrono::time_point<std::chrono::system_clock> val,
+              FormatContext& ctx) -> decltype(ctx.out()) {
+    std::tm time = localtime(val);
+    return formatter<std::tm, Char>::format(time, ctx);
+  }
+};
+
 template <typename Char> struct formatter<std::tm, Char> {
   template <typename ParseContext>
   auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {

oss/fmt/include/fmt/color.h

@@ -463,16 +463,16 @@ template <> inline void reset_color<wchar_t>(FILE* stream) FMT_NOEXCEPT {
 }
 
 template <typename Char>
-inline void reset_color(basic_memory_buffer<Char>& buffer) FMT_NOEXCEPT {
+inline void reset_color(buffer<Char>& buffer) FMT_NOEXCEPT {
   const char* begin = data::reset_color;
   const char* end = begin + sizeof(data::reset_color) - 1;
   buffer.append(begin, end);
 }
 
 template <typename Char>
-void vformat_to(basic_memory_buffer<Char>& buf, const text_style& ts,
+void vformat_to(buffer<Char>& buf, const text_style& ts,
                 basic_string_view<Char> format_str,
-                basic_format_args<buffer_context<Char>> args) {
+                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   bool has_style = false;
   if (ts.has_emphasis()) {
     has_style = true;
@@ -496,7 +496,7 @@ void vformat_to(basic_memory_buffer<Char>& buf, const text_style& ts,
 
 template <typename S, typename Char = char_t<S>>
 void vprint(std::FILE* f, const text_style& ts, const S& format,
-            basic_format_args<buffer_context<Char>> args) {
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buf;
   detail::vformat_to(buf, ts, to_string_view(format), args);
   buf.push_back(Char(0));
@@ -504,20 +504,22 @@ void vprint(std::FILE* f, const text_style& ts, const S& format,
 }
 
 /**
+  \rst
   Formats a string and prints it to the specified file stream using ANSI
   escape sequences to specify text formatting.
-  Example:
+
+  **Example**::
+
     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
                "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
  */
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_string<S>::value)>
 void print(std::FILE* f, const text_style& ts, const S& format_str,
            const Args&... args) {
-  detail::check_format_string<Args...>(format_str);
-  using context = buffer_context<char_t<S>>;
-  format_arg_store<context, Args...> as{args...};
-  vprint(f, ts, format_str, basic_format_args<context>(as));
+  vprint(f, ts, format_str,
+         fmt::make_args_checked<Args...>(format_str, args...));
 }
 
 /**
@@ -558,7 +560,42 @@ template <typename S, typename... Args, typename Char = char_t<S>>
 inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
                                       const Args&... args) {
   return vformat(ts, to_string_view(format_str),
-                 detail::make_args_checked<Args...>(format_str, args...));
+                 fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+/**
+  Formats a string with the given text_style and writes the output to ``out``.
+ */
+template <typename OutputIt, typename Char,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+OutputIt vformat_to(
+    OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
+  detail::vformat_to(buf, ts, format_str, args);
+  return detail::get_iterator(buf);
+}
+
+/**
+  \rst
+  Formats arguments with the given text_style, writes the result to the output
+  iterator ``out`` and returns the iterator past the end of the output range.
+
+  **Example**::
+
+    std::vector<char> out;
+    fmt::format_to(std::back_inserter(out),
+                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+  \endrst
+*/
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value&&
+              detail::is_string<S>::value>
+inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, ts, to_string_view(format_str),
+                    fmt::make_args_checked<Args...>(format_str, args...));
 }
 
 FMT_END_NAMESPACE

oss/fmt/include/fmt/compile.h

@@ -368,7 +368,8 @@ template <typename... Args> struct type_list {};
 
 // Returns a reference to the argument at index N from [first, rest...].
 template <int N, typename T, typename... Args>
-constexpr const auto& get(const T& first, const Args&... rest) {
+constexpr const auto& get([[maybe_unused]] const T& first,
+                          [[maybe_unused]] const Args&... rest) {
   static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
   if constexpr (N == 0)
     return first;
@@ -406,6 +407,19 @@ constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
   return {{&s[pos], size}};
 }
 
+template <typename Char> struct code_unit {
+  Char value;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, value);
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<code_unit<Char>> : std::true_type {};
+
 // A replacement field that refers to argument N.
 template <typename Char, typename T, int N> struct field {
   using char_type = Char;
@@ -430,7 +444,9 @@ template <typename Char, typename T, int N> struct spec_field {
   OutputIt format(OutputIt out, const Args&... args) const {
     // This ensures that the argument type is convertile to `const T&`.
     const T& arg = get<N>(args...);
-    basic_format_context<OutputIt, Char> ctx(out, {});
+    const auto& vargs =
+        make_format_args<basic_format_context<OutputIt, Char>>(args...);
+    basic_format_context<OutputIt, Char> ctx(out, vargs);
     return fmt.format(arg, ctx);
   }
 };
@@ -489,16 +505,17 @@ constexpr auto parse_tail(T head, S format_str) {
 template <typename T, typename Char> struct parse_specs_result {
   formatter<T, Char> fmt;
   size_t end;
+  int next_arg_id;
 };
 
 template <typename T, typename Char>
 constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
-                                                  size_t pos) {
+                                                  size_t pos, int arg_id) {
   str.remove_prefix(pos);
-  auto ctx = basic_format_parse_context<Char>(str);
+  auto ctx = basic_format_parse_context<Char>(str, {}, arg_id + 1);
   auto f = formatter<T, Char>();
   auto end = f.parse(ctx);
-  return {f, pos + (end - str.data()) + 1};
+  return {f, pos + (end - str.data()) + 1, ctx.next_arg_id()};
 }
 
 // Compiles a non-empty format string and returns the compiled representation
@@ -518,8 +535,8 @@ constexpr auto compile_format_string(S format_str) {
                                                format_str);
     } else if constexpr (str[POS + 1] == ':') {
       using type = get_type<ID, Args>;
-      constexpr auto result = parse_specs<type>(str, POS + 2);
-      return parse_tail<Args, result.end, ID + 1>(
+      constexpr auto result = parse_specs<type>(str, POS + 2, ID);
+      return parse_tail<Args, result.end, result.next_arg_id>(
           spec_field<char_type, type, ID>{result.fmt}, format_str);
     } else {
       return unknown_format();
@@ -530,8 +547,13 @@ constexpr auto compile_format_string(S format_str) {
     return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
   } else {
     constexpr auto end = parse_text(str, POS + 1);
-    return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
-                                     format_str);
+    if constexpr (end - POS > 1) {
+      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+                                       format_str);
+    } else {
+      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+                                       format_str);
+    }
   }
 }
 
@@ -587,8 +609,7 @@ template <typename CompiledFormat, typename... Args,
 FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
                                           const Args&... args) {
   basic_memory_buffer<Char> buffer;
-  detail::buffer<Char>& base = buffer;
-  cf.format(std::back_inserter(base), args...);
+  cf.format(detail::buffer_appender<Char>(buffer), args...);
   return to_string(buffer);
 }
 
@@ -608,8 +629,7 @@ template <typename CompiledFormat, typename... Args,
 std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
   basic_memory_buffer<Char> buffer;
   using context = buffer_context<Char>;
-  detail::buffer<Char>& base = buffer;
-  detail::cf::vformat_to<context>(std::back_inserter(base), cf,
+  detail::cf::vformat_to<context>(detail::buffer_appender<Char>(buffer), cf,
                                   make_format_args<context>(args...));
   return to_string(buffer);
 }
@@ -618,9 +638,13 @@ template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
 FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
                                                            Args&&... args) {
-  constexpr basic_string_view<typename S::char_type> str = S();
-  if (str.size() == 2 && str[0] == '{' && str[1] == '}')
-    return fmt::to_string(detail::first(args...));
+#ifdef __cpp_if_constexpr
+  if constexpr (std::is_same<typename S::char_type, char>::value) {
+    constexpr basic_string_view<typename S::char_type> str = S();
+    if (str.size() == 2 && str[0] == '{' && str[1] == '}')
+      return fmt::to_string(detail::first(args...));
+  }
+#endif
   constexpr auto compiled = detail::compile<Args...>(S());
   return format(compiled, std::forward<Args>(args)...);
 }
@@ -643,18 +667,30 @@ OutputIt format_to(OutputIt out, const S&, const Args&... args) {
   return format_to(out, compiled, args...);
 }
 
-template <
-    typename OutputIt, typename CompiledFormat, typename... Args,
-    FMT_ENABLE_IF(detail::is_output_iterator<OutputIt>::value&& std::is_base_of<
-                  detail::basic_compiled_format, CompiledFormat>::value)>
-format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
-                                         const CompiledFormat& cf,
-                                         const Args&... args) {
+template <typename OutputIt, typename CompiledFormat, typename... Args>
+auto format_to_n(OutputIt out, size_t n, const CompiledFormat& cf,
+                 const Args&... args) ->
+    typename std::enable_if<
+        detail::is_output_iterator<OutputIt,
+                                   typename CompiledFormat::char_type>::value &&
+            std::is_base_of<detail::basic_compiled_format,
+                            CompiledFormat>::value,
+        format_to_n_result<OutputIt>>::type {
   auto it =
       format_to(detail::truncating_iterator<OutputIt>(out, n), cf, args...);
   return {it.base(), it.count()};
 }
 
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n, const S&,
+                                         const Args&... args) {
+  constexpr auto compiled = detail::compile<Args...>(S());
+  auto it = format_to(detail::truncating_iterator<OutputIt>(out, n), compiled,
+                      args...);
+  return {it.base(), it.count()};
+}
+
 template <typename CompiledFormat, typename... Args>
 size_t formatted_size(const CompiledFormat& cf, const Args&... args) {
   return format_to(detail::counting_iterator(), cf, args...).count();

oss/fmt/include/fmt/core.h

@@ -18,7 +18,7 @@
 #include <vector>
 
 // The fmt library version in the form major * 10000 + minor * 100 + patch.
-#define FMT_VERSION 70001
+#define FMT_VERSION 70103
 
 #ifdef __clang__
 #  define FMT_CLANG_VERSION (__clang_major__ * 100 + __clang_minor__)
@@ -57,6 +57,7 @@
 #  define FMT_MSC_VER 0
 #  define FMT_SUPPRESS_MSC_WARNING(n)
 #endif
+
 #ifdef __has_feature
 #  define FMT_HAS_FEATURE(x) __has_feature(x)
 #else
@@ -64,7 +65,7 @@
 #endif
 
 #if defined(__has_include) && !defined(__INTELLISENSE__) && \
-    !(FMT_ICC_VERSION && FMT_ICC_VERSION < 1600)
+    (!FMT_ICC_VERSION || FMT_ICC_VERSION >= 1600)
 #  define FMT_HAS_INCLUDE(x) __has_include(x)
 #else
 #  define FMT_HAS_INCLUDE(x) 0
@@ -99,7 +100,7 @@
 #endif
 
 #ifndef FMT_OVERRIDE
-#  if FMT_HAS_FEATURE(cxx_override) || \
+#  if FMT_HAS_FEATURE(cxx_override_control) || \
       (FMT_GCC_VERSION >= 408 && FMT_HAS_GXX_CXX11) || FMT_MSC_VER >= 1900
 #    define FMT_OVERRIDE override
 #  else
@@ -152,7 +153,7 @@
 #  if FMT_HAS_CPP14_ATTRIBUTE(deprecated) || FMT_MSC_VER >= 1900
 #    define FMT_DEPRECATED [[deprecated]]
 #  else
-#    if defined(__GNUC__) || defined(__clang__)
+#    if (defined(__GNUC__) && !defined(__LCC__)) || defined(__clang__)
 #      define FMT_DEPRECATED __attribute__((deprecated))
 #    elif FMT_MSC_VER
 #      define FMT_DEPRECATED __declspec(deprecated)
@@ -177,9 +178,17 @@
 #  endif
 #endif
 
-#ifndef FMT_BEGIN_NAMESPACE
+#ifndef FMT_USE_INLINE_NAMESPACES
 #  if FMT_HAS_FEATURE(cxx_inline_namespaces) || FMT_GCC_VERSION >= 404 || \
-      FMT_MSC_VER >= 1900
+      (FMT_MSC_VER >= 1900 && !_MANAGED)
+#    define FMT_USE_INLINE_NAMESPACES 1
+#  else
+#    define FMT_USE_INLINE_NAMESPACES 0
+#  endif
+#endif
+
+#ifndef FMT_BEGIN_NAMESPACE
+#  if FMT_USE_INLINE_NAMESPACES
 #    define FMT_INLINE_NAMESPACE inline namespace
 #    define FMT_END_NAMESPACE \
       }                       \
@@ -269,8 +278,7 @@ struct monostate {};
 
 namespace detail {
 
-// A helper function to suppress bogus "conditional expression is constant"
-// warnings.
+// A helper function to suppress "conditional expression is constant" warnings.
 template <typename T> constexpr T const_check(T value) { return value; }
 
 FMT_NORETURN FMT_API void assert_fail(const char* file, int line,
@@ -299,7 +307,8 @@ template <typename T> struct std_string_view {};
 
 #ifdef FMT_USE_INT128
 // Do nothing.
-#elif defined(__SIZEOF_INT128__) && !FMT_NVCC
+#elif defined(__SIZEOF_INT128__) && !FMT_NVCC && \
+    !(FMT_CLANG_VERSION && FMT_MSC_VER)
 #  define FMT_USE_INT128 1
 using int128_t = __int128_t;
 using uint128_t = __uint128_t;
@@ -506,6 +515,18 @@ template <typename S> struct char_t_impl<S, enable_if_t<is_string<S>::value>> {
   using type = typename result::value_type;
 };
 
+// Reports a compile-time error if S is not a valid format string.
+template <typename..., typename S, FMT_ENABLE_IF(!is_compile_string<S>::value)>
+FMT_INLINE void check_format_string(const S&) {
+#ifdef FMT_ENFORCE_COMPILE_STRING
+  static_assert(is_compile_string<S>::value,
+                "FMT_ENFORCE_COMPILE_STRING requires all format strings to use "
+                "FMT_STRING.");
+#endif
+}
+template <typename..., typename S, FMT_ENABLE_IF(is_compile_string<S>::value)>
+void check_format_string(S);
+
 struct error_handler {
   constexpr error_handler() = default;
   constexpr error_handler(const error_handler&) = default;
@@ -545,8 +566,9 @@ class basic_format_parse_context : private ErrorHandler {
   using iterator = typename basic_string_view<Char>::iterator;
 
   explicit constexpr basic_format_parse_context(
-      basic_string_view<Char> format_str, ErrorHandler eh = {})
-      : ErrorHandler(eh), format_str_(format_str), next_arg_id_(0) {}
+      basic_string_view<Char> format_str, ErrorHandler eh = {},
+      int next_arg_id = 0)
+      : ErrorHandler(eh), format_str_(format_str), next_arg_id_(next_arg_id) {}
 
   /**
     Returns an iterator to the beginning of the format string range being
@@ -616,8 +638,24 @@ template <typename T, typename Context>
 using has_formatter =
     std::is_constructible<typename Context::template formatter_type<T>>;
 
+// Checks whether T is a container with contiguous storage.
+template <typename T> struct is_contiguous : std::false_type {};
+template <typename Char>
+struct is_contiguous<std::basic_string<Char>> : std::true_type {};
+
 namespace detail {
 
+// Extracts a reference to the container from back_insert_iterator.
+template <typename Container>
+inline Container& get_container(std::back_insert_iterator<Container> it) {
+  using bi_iterator = std::back_insert_iterator<Container>;
+  struct accessor : bi_iterator {
+    accessor(bi_iterator iter) : bi_iterator(iter) {}
+    using bi_iterator::container;
+  };
+  return *accessor(it).container;
+}
+
 /**
   \rst
   A contiguous memory buffer with an optional growing ability. It is an internal
@@ -640,6 +678,8 @@ template <typename T> class buffer {
         size_(sz),
         capacity_(cap) {}
 
+  ~buffer() = default;
+
   /** Sets the buffer data and capacity. */
   void set(T* buf_data, size_t buf_capacity) FMT_NOEXCEPT {
     ptr_ = buf_data;
@@ -655,7 +695,6 @@ template <typename T> class buffer {
 
   buffer(const buffer&) = delete;
   void operator=(const buffer&) = delete;
-  virtual ~buffer() = default;
 
   T* begin() FMT_NOEXCEPT { return ptr_; }
   T* end() FMT_NOEXCEPT { return ptr_ + size_; }
@@ -675,24 +714,26 @@ template <typename T> class buffer {
   /** Returns a pointer to the buffer data. */
   const T* data() const FMT_NOEXCEPT { return ptr_; }
 
-  /**
-    Resizes the buffer. If T is a POD type new elements may not be initialized.
-   */
-  void resize(size_t new_size) {
-    reserve(new_size);
-    size_ = new_size;
-  }
-
   /** Clears this buffer. */
   void clear() { size_ = 0; }
 
-  /** Reserves space to store at least *capacity* elements. */
-  void reserve(size_t new_capacity) {
+  // Tries resizing the buffer to contain *count* elements. If T is a POD type
+  // the new elements may not be initialized.
+  void try_resize(size_t count) {
+    try_reserve(count);
+    size_ = count <= capacity_ ? count : capacity_;
+  }
+
+  // Tries increasing the buffer capacity to *new_capacity*. It can increase the
+  // capacity by a smaller amount than requested but guarantees there is space
+  // for at least one additional element either by increasing the capacity or by
+  // flushing the buffer if it is full.
+  void try_reserve(size_t new_capacity) {
     if (new_capacity > capacity_) grow(new_capacity);
   }
 
   void push_back(const T& value) {
-    reserve(size_ + 1);
+    try_reserve(size_ + 1);
     ptr_[size_++] = value;
   }
 
@@ -705,32 +746,150 @@ template <typename T> class buffer {
   }
 };
 
-// A container-backed buffer.
+struct buffer_traits {
+  explicit buffer_traits(size_t) {}
+  size_t count() const { return 0; }
+  size_t limit(size_t size) { return size; }
+};
+
+class fixed_buffer_traits {
+ private:
+  size_t count_ = 0;
+  size_t limit_;
+
+ public:
+  explicit fixed_buffer_traits(size_t limit) : limit_(limit) {}
+  size_t count() const { return count_; }
+  size_t limit(size_t size) {
+    size_t n = limit_ > count_ ? limit_ - count_ : 0;
+    count_ += size;
+    return size < n ? size : n;
+  }
+};
+
+// A buffer that writes to an output iterator when flushed.
+template <typename OutputIt, typename T, typename Traits = buffer_traits>
+class iterator_buffer final : public Traits, public buffer<T> {
+ private:
+  OutputIt out_;
+  enum { buffer_size = 256 };
+  T data_[buffer_size];
+
+ protected:
+  void grow(size_t) final FMT_OVERRIDE {
+    if (this->size() == buffer_size) flush();
+  }
+  void flush();
+
+ public:
+  explicit iterator_buffer(OutputIt out, size_t n = buffer_size)
+      : Traits(n),
+        buffer<T>(data_, 0, buffer_size),
+        out_(out) {}
+  ~iterator_buffer() { flush(); }
+
+  OutputIt out() {
+    flush();
+    return out_;
+  }
+  size_t count() const { return Traits::count() + this->size(); }
+};
+
+template <typename T> class iterator_buffer<T*, T> final : public buffer<T> {
+ protected:
+  void grow(size_t) final FMT_OVERRIDE {}
+
+ public:
+  explicit iterator_buffer(T* out, size_t = 0) : buffer<T>(out, 0, ~size_t()) {}
+
+  T* out() { return &*this->end(); }
+};
+
+// A buffer that writes to a container with the contiguous storage.
 template <typename Container>
-class container_buffer : public buffer<typename Container::value_type> {
+class iterator_buffer<std::back_insert_iterator<Container>,
+                      enable_if_t<is_contiguous<Container>::value,
+                                  typename Container::value_type>>
+    final : public buffer<typename Container::value_type> {
  private:
   Container& container_;
 
  protected:
-  void grow(size_t capacity) FMT_OVERRIDE {
+  void grow(size_t capacity) final FMT_OVERRIDE {
     container_.resize(capacity);
     this->set(&container_[0], capacity);
   }
 
  public:
-  explicit container_buffer(Container& c)
+  explicit iterator_buffer(Container& c)
       : buffer<typename Container::value_type>(c.size()), container_(c) {}
+  explicit iterator_buffer(std::back_insert_iterator<Container> out, size_t = 0)
+      : iterator_buffer(get_container(out)) {}
+  std::back_insert_iterator<Container> out() {
+    return std::back_inserter(container_);
+  }
 };
 
-// Extracts a reference to the container from back_insert_iterator.
-template <typename Container>
-inline Container& get_container(std::back_insert_iterator<Container> it) {
-  using bi_iterator = std::back_insert_iterator<Container>;
-  struct accessor : bi_iterator {
-    accessor(bi_iterator iter) : bi_iterator(iter) {}
-    using bi_iterator::container;
-  };
-  return *accessor(it).container;
+// A buffer that counts the number of code units written discarding the output.
+template <typename T = char> class counting_buffer final : public buffer<T> {
+ private:
+  enum { buffer_size = 256 };
+  T data_[buffer_size];
+  size_t count_ = 0;
+
+ protected:
+  void grow(size_t) final FMT_OVERRIDE {
+    if (this->size() != buffer_size) return;
+    count_ += this->size();
+    this->clear();
+  }
+
+ public:
+  counting_buffer() : buffer<T>(data_, 0, buffer_size) {}
+
+  size_t count() { return count_ + this->size(); }
+};
+
+// An output iterator that appends to the buffer.
+// It is used to reduce symbol sizes for the common case.
+template <typename T>
+class buffer_appender : public std::back_insert_iterator<buffer<T>> {
+  using base = std::back_insert_iterator<buffer<T>>;
+
+ public:
+  explicit buffer_appender(buffer<T>& buf) : base(buf) {}
+  buffer_appender(base it) : base(it) {}
+
+  buffer_appender& operator++() {
+    base::operator++();
+    return *this;
+  }
+
+  buffer_appender operator++(int) {
+    buffer_appender tmp = *this;
+    ++*this;
+    return tmp;
+  }
+};
+
+// Maps an output iterator into a buffer.
+template <typename T, typename OutputIt>
+iterator_buffer<OutputIt, T> get_buffer(OutputIt);
+template <typename T> buffer<T>& get_buffer(buffer_appender<T>);
+
+template <typename OutputIt> OutputIt get_buffer_init(OutputIt out) {
+  return out;
+}
+template <typename T> buffer<T>& get_buffer_init(buffer_appender<T> out) {
+  return get_container(out);
+}
+
+template <typename Buffer>
+auto get_iterator(Buffer& buf) -> decltype(buf.out()) {
+  return buf.out();
+}
+template <typename T> buffer_appender<T> get_iterator(buffer<T>& buf) {
+  return buffer_appender<T>(buf);
 }
 
 template <typename T, typename Char = char, typename Enable = void>
@@ -759,7 +918,8 @@ template <typename Char> struct named_arg_info {
 template <typename T, typename Char, size_t NUM_ARGS, size_t NUM_NAMED_ARGS>
 struct arg_data {
   // args_[0].named_args points to named_args_ to avoid bloating format_args.
-  T args_[1 + (NUM_ARGS != 0 ? NUM_ARGS : 1)];
+  // +1 to workaround a bug in gcc 7.5 that causes duplicated-branches warning.
+  T args_[1 + (NUM_ARGS != 0 ? NUM_ARGS : +1)];
   named_arg_info<Char> named_args_[NUM_NAMED_ARGS];
 
   template <typename... U>
@@ -771,7 +931,8 @@ struct arg_data {
 
 template <typename T, typename Char, size_t NUM_ARGS>
 struct arg_data<T, Char, NUM_ARGS, 0> {
-  T args_[NUM_ARGS != 0 ? NUM_ARGS : 1];
+  // +1 to workaround a bug in gcc 7.5 that causes duplicated-branches warning.
+  T args_[NUM_ARGS != 0 ? NUM_ARGS : +1];
 
   template <typename... U>
   FMT_INLINE arg_data(const U&... init) : args_{init...} {}
@@ -959,6 +1120,8 @@ enum { long_short = sizeof(long) == sizeof(int) };
 using long_type = conditional_t<long_short, int, long long>;
 using ulong_type = conditional_t<long_short, unsigned, unsigned long long>;
 
+struct unformattable {};
+
 // Maps formatting arguments to core types.
 template <typename Context> struct arg_mapper {
   using char_type = typename Context::char_type;
@@ -1067,15 +1230,7 @@ template <typename Context> struct arg_mapper {
     return map(val.value);
   }
 
-  int map(...) {
-    constexpr bool formattable = sizeof(Context) == 0;
-    static_assert(
-        formattable,
-        "Cannot format argument. To make type T formattable provide a "
-        "formatter<T> specialization: "
-        "https://fmt.dev/latest/api.html#formatting-user-defined-types");
-    return 0;
-  }
+  unformattable map(...) { return {}; }
 };
 
 // A type constant after applying arg_mapper<Context>.
@@ -1199,15 +1354,25 @@ FMT_CONSTEXPR_DECL FMT_INLINE auto visit_format_arg(
   return vis(monostate());
 }
 
-// Checks whether T is a container with contiguous storage.
-template <typename T> struct is_contiguous : std::false_type {};
-template <typename Char>
-struct is_contiguous<std::basic_string<Char>> : std::true_type {};
-template <typename Char>
-struct is_contiguous<detail::buffer<Char>> : std::true_type {};
+template <typename T> struct formattable : std::false_type {};
 
 namespace detail {
 
+// A workaround for gcc 4.8 to make void_t work in a SFINAE context.
+template <typename... Ts> struct void_t_impl { using type = void; };
+template <typename... Ts>
+using void_t = typename detail::void_t_impl<Ts...>::type;
+
+template <typename It, typename T, typename Enable = void>
+struct is_output_iterator : std::false_type {};
+
+template <typename It, typename T>
+struct is_output_iterator<
+    It, T,
+    void_t<typename std::iterator_traits<It>::iterator_category,
+           decltype(*std::declval<It>() = std::declval<T>())>>
+    : std::true_type {};
+
 template <typename OutputIt>
 struct is_back_insert_iterator : std::false_type {};
 template <typename Container>
@@ -1219,6 +1384,9 @@ struct is_contiguous_back_insert_iterator : std::false_type {};
 template <typename Container>
 struct is_contiguous_back_insert_iterator<std::back_insert_iterator<Container>>
     : is_contiguous<Container> {};
+template <typename Char>
+struct is_contiguous_back_insert_iterator<buffer_appender<Char>>
+    : std::true_type {};
 
 // A type-erased reference to an std::locale to avoid heavy <locale> include.
 class locale_ref {
@@ -1250,13 +1418,24 @@ FMT_CONSTEXPR basic_format_arg<Context> make_arg(const T& value) {
   return arg;
 }
 
+template <typename T> int check(unformattable) {
+  static_assert(
+      formattable<T>(),
+      "Cannot format an argument. To make type T formattable provide a "
+      "formatter<T> specialization: https://fmt.dev/latest/api.html#udt");
+  return 0;
+}
+template <typename T, typename U> inline const U& check(const U& val) {
+  return val;
+}
+
 // The type template parameter is there to avoid an ODR violation when using
 // a fallback formatter in one translation unit and an implicit conversion in
 // another (not recommended).
 template <bool IS_PACKED, typename Context, type, typename T,
           FMT_ENABLE_IF(IS_PACKED)>
 inline value<Context> make_arg(const T& val) {
-  return arg_mapper<Context>().map(val);
+  return check<T>(arg_mapper<Context>().map(val));
 }
 
 template <bool IS_PACKED, typename Context, type, typename T,
@@ -1356,13 +1535,13 @@ template <typename OutputIt, typename Char> class basic_format_context {
 
 template <typename Char>
 using buffer_context =
-    basic_format_context<std::back_insert_iterator<detail::buffer<Char>>, Char>;
+    basic_format_context<detail::buffer_appender<Char>, Char>;
 using format_context = buffer_context<char>;
 using wformat_context = buffer_context<wchar_t>;
 
-// Workaround a bug in gcc: https://stackoverflow.com/q/62767544/471164.
+// Workaround an alias issue: https://stackoverflow.com/q/62767544/471164.
 #define FMT_BUFFER_CONTEXT(Char) \
-  basic_format_context<std::back_insert_iterator<detail::buffer<Char>>, Char>
+  basic_format_context<detail::buffer_appender<Char>, Char>
 
 /**
   \rst
@@ -1414,7 +1593,7 @@ class format_arg_store
 
 /**
   \rst
-  Constructs an `~fmt::format_arg_store` object that contains references to
+  Constructs a `~fmt::format_arg_store` object that contains references to
   arguments and can be implicitly converted to `~fmt::format_args`. `Context`
   can be omitted in which case it defaults to `~fmt::context`.
   See `~fmt::arg` for lifetime considerations.
@@ -1426,6 +1605,27 @@ inline format_arg_store<Context, Args...> make_format_args(
   return {args...};
 }
 
+/**
+  \rst
+  Constructs a `~fmt::format_arg_store` object that contains references
+  to arguments and can be implicitly converted to `~fmt::format_args`.
+  If ``format_str`` is a compile-time string then `make_args_checked` checks
+  its validity at compile time.
+  \endrst
+ */
+template <typename... Args, typename S, typename Char = char_t<S>>
+inline auto make_args_checked(const S& format_str,
+                              const remove_reference_t<Args>&... args)
+    -> format_arg_store<buffer_context<Char>, remove_reference_t<Args>...> {
+  static_assert(
+      detail::count<(
+              std::is_base_of<detail::view, remove_reference_t<Args>>::value &&
+              std::is_reference<Args>::value)...>() == 0,
+      "passing views as lvalues is disallowed");
+  detail::check_format_string<Args...>(format_str);
+  return {args...};
+}
+
 /**
   \rst
   Returns a named argument to be used in a formatting function. It should only
@@ -1713,7 +1913,7 @@ template <typename Context> class basic_format_args {
   }
 
   template <typename Char> int get_id(basic_string_view<Char> name) const {
-    if (!has_named_args()) return {};
+    if (!has_named_args()) return -1;
     const auto& named_args =
         (is_packed() ? values_[-1] : args_[-1].value_).named_args;
     for (size_t i = 0; i < named_args.size; ++i) {
@@ -1729,7 +1929,14 @@ template <typename Context> class basic_format_args {
   }
 };
 
-/** An alias to ``basic_format_args<context>``. */
+#ifdef FMT_ARM_ABI_COMPATIBILITY
+/** An alias to ``basic_format_args<format_context>``. */
+// Separate types would result in shorter symbols but break ABI compatibility
+// between clang and gcc on ARM (#1919).
+using format_args = basic_format_args<format_context>;
+using wformat_args = basic_format_args<wformat_context>;
+#else
+// DEPRECATED! These are kept for ABI compatibility.
 // It is a separate type rather than an alias to make symbols readable.
 struct format_args : basic_format_args<format_context> {
   template <typename... Args>
@@ -1738,32 +1945,10 @@ struct format_args : basic_format_args<format_context> {
 struct wformat_args : basic_format_args<wformat_context> {
   using basic_format_args::basic_format_args;
 };
+#endif
 
 namespace detail {
 
-// Reports a compile-time error if S is not a valid format string.
-template <typename..., typename S, FMT_ENABLE_IF(!is_compile_string<S>::value)>
-FMT_INLINE void check_format_string(const S&) {
-#ifdef FMT_ENFORCE_COMPILE_STRING
-  static_assert(is_compile_string<S>::value,
-                "FMT_ENFORCE_COMPILE_STRING requires all format strings to use "
-                "FMT_STRING.");
-#endif
-}
-template <typename..., typename S, FMT_ENABLE_IF(is_compile_string<S>::value)>
-void check_format_string(S);
-
-template <typename... Args, typename S, typename Char = char_t<S>>
-inline format_arg_store<buffer_context<Char>, remove_reference_t<Args>...>
-make_args_checked(const S& format_str,
-                  const remove_reference_t<Args>&... args) {
-  static_assert(count<(std::is_base_of<view, remove_reference_t<Args>>::value &&
-                       std::is_reference<Args>::value)...>() == 0,
-                "passing views as lvalues is disallowed");
-  check_format_string<Args...>(format_str);
-  return {args...};
-}
-
 template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
 std::basic_string<Char> vformat(
     basic_string_view<Char> format_str,
@@ -1772,9 +1957,10 @@ std::basic_string<Char> vformat(
 FMT_API std::string vformat(string_view format_str, format_args args);
 
 template <typename Char>
-typename FMT_BUFFER_CONTEXT(Char)::iterator vformat_to(
+void vformat_to(
     buffer<Char>& buf, basic_string_view<Char> format_str,
-    basic_format_args<FMT_BUFFER_CONTEXT(type_identity_t<Char>)> args);
+    basic_format_args<FMT_BUFFER_CONTEXT(type_identity_t<Char>)> args,
+    detail::locale_ref loc = {});
 
 template <typename Char, typename Args,
           FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
@@ -1789,26 +1975,80 @@ inline void vprint_mojibake(std::FILE*, string_view, format_args) {}
 /** Formats a string and writes the output to ``out``. */
 // GCC 8 and earlier cannot handle std::back_insert_iterator<Container> with
 // vformat_to<ArgFormatter>(...) overload, so SFINAE on iterator type instead.
-template <
-    typename OutputIt, typename S, typename Char = char_t<S>,
-    FMT_ENABLE_IF(detail::is_contiguous_back_insert_iterator<OutputIt>::value)>
-OutputIt vformat_to(
-    OutputIt out, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  auto& c = detail::get_container(out);
-  detail::container_buffer<remove_reference_t<decltype(c)>> buf(c);
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          bool enable = detail::is_output_iterator<OutputIt, Char>::value>
+auto vformat_to(OutputIt out, const S& format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> typename std::enable_if<enable, OutputIt>::type {
+  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
   detail::vformat_to(buf, to_string_view(format_str), args);
-  return out;
+  return detail::get_iterator(buf);
 }
 
-template <typename Container, typename S, typename... Args,
-          FMT_ENABLE_IF(
-              is_contiguous<Container>::value&& detail::is_string<S>::value)>
-inline std::back_insert_iterator<Container> format_to(
-    std::back_insert_iterator<Container> out, const S& format_str,
-    Args&&... args) {
-  return vformat_to(out, to_string_view(format_str),
-                    detail::make_args_checked<Args...>(format_str, args...));
+/**
+ \rst
+ Formats arguments, writes the result to the output iterator ``out`` and returns
+ the iterator past the end of the output range.
+
+ **Example**::
+
+   std::vector<char> out;
+   fmt::format_to(std::back_inserter(out), "{}", 42);
+ \endrst
+ */
+// We cannot use FMT_ENABLE_IF because of a bug in gcc 8.3.
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value>
+inline auto format_to(OutputIt out, const S& format_str, Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat_to(out, to_string_view(format_str), vargs);
+}
+
+template <typename OutputIt> struct format_to_n_result {
+  /** Iterator past the end of the output range. */
+  OutputIt out;
+  /** Total (not truncated) output size. */
+  size_t size;
+};
+
+template <typename OutputIt, typename Char, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+inline format_to_n_result<OutputIt> vformat_to_n(
+    OutputIt out, size_t n, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
+                                                                           n);
+  detail::vformat_to(buf, format_str, args);
+  return {buf.out(), buf.count()};
+}
+
+/**
+ \rst
+ Formats arguments, writes up to ``n`` characters of the result to the output
+ iterator ``out`` and returns the total output size and the iterator past the
+ end of the output range.
+ \endrst
+ */
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value>
+inline auto format_to_n(OutputIt out, size_t n, const S& format_str,
+                        const Args&... args) ->
+    typename std::enable_if<enable, format_to_n_result<OutputIt>>::type {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat_to_n(out, n, to_string_view(format_str), vargs);
+}
+
+/**
+  Returns the number of characters in the output of
+  ``format(format_str, args...)``.
+ */
+template <typename... Args>
+inline size_t formatted_size(string_view format_str, Args&&... args) {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  detail::counting_buffer<> buf;
+  detail::vformat_to(buf, format_str, vargs);
+  return buf.count();
 }
 
 template <typename S, typename Char = char_t<S>>
@@ -1832,7 +2072,7 @@ FMT_INLINE std::basic_string<Char> vformat(
 // std::basic_string<char_t<S>> to reduce the symbol size.
 template <typename S, typename... Args, typename Char = char_t<S>>
 FMT_INLINE std::basic_string<Char> format(const S& format_str, Args&&... args) {
-  const auto& vargs = detail::make_args_checked<Args...>(format_str, args...);
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
   return detail::vformat(to_string_view(format_str), vargs);
 }
 
@@ -1852,7 +2092,7 @@ FMT_API void vprint(std::FILE*, string_view, format_args);
  */
 template <typename S, typename... Args, typename Char = char_t<S>>
 inline void print(std::FILE* f, const S& format_str, Args&&... args) {
-  const auto& vargs = detail::make_args_checked<Args...>(format_str, args...);
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
   return detail::is_unicode<Char>()
              ? vprint(f, to_string_view(format_str), vargs)
              : detail::vprint_mojibake(f, to_string_view(format_str), vargs);
@@ -1871,7 +2111,7 @@ inline void print(std::FILE* f, const S& format_str, Args&&... args) {
  */
 template <typename S, typename... Args, typename Char = char_t<S>>
 inline void print(const S& format_str, Args&&... args) {
-  const auto& vargs = detail::make_args_checked<Args...>(format_str, args...);
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
   return detail::is_unicode<Char>()
              ? vprint(to_string_view(format_str), vargs)
              : detail::vprint_mojibake(stdout, to_string_view(format_str),

oss/fmt/include/fmt/locale.h

@@ -15,22 +15,12 @@
 FMT_BEGIN_NAMESPACE
 
 namespace detail {
-template <typename Char>
-typename buffer_context<Char>::iterator vformat_to(
-    const std::locale& loc, buffer<Char>& buf,
-    basic_string_view<Char> format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  using af = arg_formatter<typename buffer_context<Char>::iterator, Char>;
-  return vformat_to<af>(std::back_inserter(buf), to_string_view(format_str),
-                        args, detail::locale_ref(loc));
-}
-
 template <typename Char>
 std::basic_string<Char> vformat(
     const std::locale& loc, basic_string_view<Char> format_str,
     basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buffer;
-  detail::vformat_to(loc, buffer, format_str, args);
+  detail::vformat_to(buffer, format_str, args, detail::locale_ref(loc));
   return fmt::to_string(buffer);
 }
 }  // namespace detail
@@ -45,32 +35,28 @@ inline std::basic_string<Char> vformat(
 template <typename S, typename... Args, typename Char = char_t<S>>
 inline std::basic_string<Char> format(const std::locale& loc,
                                       const S& format_str, Args&&... args) {
-  return detail::vformat(
-      loc, to_string_view(format_str),
-      detail::make_args_checked<Args...>(format_str, args...));
+  return detail::vformat(loc, to_string_view(format_str),
+                         fmt::make_args_checked<Args...>(format_str, args...));
 }
 
 template <typename S, typename OutputIt, typename... Args,
-          typename Char = enable_if_t<
-              detail::is_output_iterator<OutputIt>::value, char_t<S>>>
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
 inline OutputIt vformat_to(
     OutputIt out, const std::locale& loc, const S& format_str,
-    format_args_t<type_identity_t<OutputIt>, Char> args) {
-  using af = detail::arg_formatter<OutputIt, Char>;
-  return vformat_to<af>(out, to_string_view(format_str), args,
-                        detail::locale_ref(loc));
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
+  vformat_to(buf, to_string_view(format_str), args, detail::locale_ref(loc));
+  return detail::get_iterator(buf);
 }
 
 template <typename OutputIt, typename S, typename... Args,
-          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt>::value&&
-                            detail::is_string<S>::value)>
-inline OutputIt format_to(OutputIt out, const std::locale& loc,
-                          const S& format_str, Args&&... args) {
-  detail::check_format_string<Args...>(format_str);
-  using context = format_context_t<OutputIt, char_t<S>>;
-  format_arg_store<context, Args...> as{args...};
-  return vformat_to(out, loc, to_string_view(format_str),
-                    basic_format_args<context>(as));
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value>
+inline auto format_to(OutputIt out, const std::locale& loc,
+                      const S& format_str, Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat_to(out, loc, to_string_view(format_str), vargs);
 }
 
 FMT_END_NAMESPACE

oss/fmt/include/fmt/os.h

@@ -29,7 +29,8 @@
 #if FMT_HAS_INCLUDE("winapifamily.h")
 #  include <winapifamily.h>
 #endif
-#if FMT_HAS_INCLUDE("fcntl.h") && \
+#if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
+     defined(__linux__)) &&                              \
     (!defined(WINAPI_FAMILY) || (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
 #  include <fcntl.h>  // for O_RDONLY
 #  define FMT_USE_FCNTL 1
@@ -278,7 +279,8 @@ class file {
     RDONLY = FMT_POSIX(O_RDONLY),  // Open for reading only.
     WRONLY = FMT_POSIX(O_WRONLY),  // Open for writing only.
     RDWR = FMT_POSIX(O_RDWR),      // Open for reading and writing.
-    CREATE = FMT_POSIX(O_CREAT)    // Create if the file doesn't exist.
+    CREATE = FMT_POSIX(O_CREAT),   // Create if the file doesn't exist.
+    APPEND = FMT_POSIX(O_APPEND)   // Open in append mode.
   };
 
   // Constructs a file object which doesn't represent any file.
@@ -343,36 +345,69 @@ class file {
 // Returns the memory page size.
 long getpagesize();
 
-class direct_buffered_file;
+namespace detail {
 
-template <typename S, typename... Args>
-void print(direct_buffered_file& f, const S& format_str,
-           const Args&... args);
+struct buffer_size {
+  size_t value = 0;
+  buffer_size operator=(size_t val) const {
+    auto bs = buffer_size();
+    bs.value = val;
+    return bs;
+  }
+};
 
-// A buffered file with a direct buffer access and no synchronization.
-class direct_buffered_file {
+struct ostream_params {
+  int oflag = file::WRONLY | file::CREATE;
+  size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
+
+  ostream_params() {}
+
+  template <typename... T>
+  ostream_params(T... params, int oflag) : ostream_params(params...) {
+    this->oflag = oflag;
+  }
+
+  template <typename... T>
+  ostream_params(T... params, detail::buffer_size bs)
+      : ostream_params(params...) {
+    this->buffer_size = bs.value;
+  }
+};
+}  // namespace detail
+
+static constexpr detail::buffer_size buffer_size;
+
+// A fast output stream which is not thread-safe.
+class ostream final : private detail::buffer<char> {
  private:
   file file_;
 
-  enum { buffer_size = 4096 };
-  char buffer_[buffer_size];
-  int pos_;
-
   void flush() {
-    if (pos_ == 0) return;
-    file_.write(buffer_, pos_);
-    pos_ = 0;
+    if (size() == 0) return;
+    file_.write(data(), size());
+    clear();
   }
 
-  int free_capacity() const { return buffer_size - pos_; }
+  FMT_API void grow(size_t) override final;
+
+  ostream(cstring_view path, const detail::ostream_params& params)
+      : file_(path, params.oflag) {
+    set(new char[params.buffer_size], params.buffer_size);
+  }
 
  public:
-  direct_buffered_file(cstring_view path, int oflag)
-    : file_(path, oflag), pos_(0) {}
-
-  ~direct_buffered_file() {
-    flush();
+  ostream(ostream&& other)
+      : detail::buffer<char>(other.data(), other.size(), other.capacity()),
+        file_(std::move(other.file_)) {
+    other.set(nullptr, 0);
   }
+  ~ostream() {
+    flush();
+    delete[] data();
+  }
+
+  template <typename... T>
+  friend ostream output_file(cstring_view path, T... params);
 
   void close() {
     flush();
@@ -380,25 +415,20 @@ class direct_buffered_file {
   }
 
   template <typename S, typename... Args>
-  friend void print(direct_buffered_file& f, const S& format_str,
-                    const Args&... args) {
-    // We could avoid double buffering.
-    auto buf = fmt::memory_buffer();
-    fmt::format_to(std::back_inserter(buf), format_str, args...);
-    auto remaining_pos = 0;
-    auto remaining_size = buf.size();
-    while (remaining_size > detail::to_unsigned(f.free_capacity())) {
-      auto size = f.free_capacity();
-      memcpy(f.buffer_ + f.pos_, buf.data() + remaining_pos, size);
-      f.pos_ += size;
-      f.flush();
-      remaining_pos += size;
-      remaining_size -= size;
-    }
-    memcpy(f.buffer_ + f.pos_, buf.data() + remaining_pos, remaining_size);
-    f.pos_ += static_cast<int>(remaining_size);
+  void print(const S& format_str, const Args&... args) {
+    format_to(detail::buffer_appender<char>(*this), format_str, args...);
   }
 };
+
+/**
+  Opens a file for writing. Supported parameters passed in `params`:
+  * ``<integer>``: Output flags (``file::WRONLY | file::CREATE`` by default)
+  * ``buffer_size=<integer>``: Output buffer size
+ */
+template <typename... T>
+inline ostream output_file(cstring_view path, T... params) {
+  return {path, detail::ostream_params(params...)};
+}
 #endif  // FMT_USE_FCNTL
 
 #ifdef FMT_LOCALE

oss/fmt/include/fmt/ostream.h

@@ -49,17 +49,27 @@ template <class Char> class formatbuf : public std::basic_streambuf<Char> {
   }
 };
 
+struct converter {
+  template <typename T, FMT_ENABLE_IF(is_integral<T>::value)> converter(T);
+};
+
 template <typename Char> struct test_stream : std::basic_ostream<Char> {
  private:
-  // Hide all operator<< from std::basic_ostream<Char>.
-  void_t<> operator<<(null<>);
-  void_t<> operator<<(const Char*);
-
-  template <typename T, FMT_ENABLE_IF(std::is_convertible<T, int>::value &&
-                                      !std::is_enum<T>::value)>
-  void_t<> operator<<(T);
+  void_t<> operator<<(converter);
 };
 
+// Hide insertion operators for built-in types.
+template <typename Char, typename Traits>
+void_t<> operator<<(std::basic_ostream<Char, Traits>&, Char);
+template <typename Char, typename Traits>
+void_t<> operator<<(std::basic_ostream<Char, Traits>&, char);
+template <typename Traits>
+void_t<> operator<<(std::basic_ostream<char, Traits>&, char);
+template <typename Traits>
+void_t<> operator<<(std::basic_ostream<char, Traits>&, signed char);
+template <typename Traits>
+void_t<> operator<<(std::basic_ostream<char, Traits>&, unsigned char);
+
 // Checks if T has a user-defined operator<< (e.g. not a member of
 // std::ostream).
 template <typename T, typename Char> class is_streamable {
@@ -103,7 +113,7 @@ void format_value(buffer<Char>& buf, const T& value,
 #endif
   output << value;
   output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
-  buf.resize(buf.size());
+  buf.try_resize(buf.size());
 }
 
 // Formats an object of type T that has an overloaded ostream operator<<.
@@ -160,7 +170,7 @@ template <typename S, typename... Args,
           typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
 void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {
   vprint(os, to_string_view(format_str),
-         detail::make_args_checked<Args...>(format_str, args...));
+         fmt::make_args_checked<Args...>(format_str, args...));
 }
 FMT_END_NAMESPACE
 

oss/fmt/include/fmt/printf.h

@@ -181,7 +181,7 @@ template <typename Char> class printf_width_handler {
 template <typename Char, typename Context>
 void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
              basic_format_args<Context> args) {
-  Context(std::back_inserter(buf), format, args).format();
+  Context(buffer_appender<Char>(buf), format, args).format();
 }
 }  // namespace detail
 
@@ -598,7 +598,7 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
 
 template <typename Char>
 using basic_printf_context_t =
-    basic_printf_context<std::back_insert_iterator<detail::buffer<Char>>, Char>;
+    basic_printf_context<detail::buffer_appender<Char>, Char>;
 
 using printf_context = basic_printf_context_t<char>;
 using wprintf_context = basic_printf_context_t<wchar_t>;

oss/fmt/include/fmt/ranges.h

@@ -157,6 +157,9 @@ template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
   for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
 }
 
+template <typename Range>
+using value_type = remove_cvref_t<decltype(*std::declval<Range>().begin())>;
+
 template <typename Arg, FMT_ENABLE_IF(!is_like_std_string<
                                       typename std::decay<Arg>::type>::value)>
 FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) {
@@ -182,7 +185,6 @@ FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char) {
 FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t) {
   return add_space ? L" '{}'" : L"'{}'";
 }
-
 }  // namespace detail
 
 template <typename T> struct is_tuple_like {
@@ -246,9 +248,18 @@ template <typename T, typename Char> struct is_range {
       !std::is_constructible<detail::std_string_view<Char>, T>::value;
 };
 
-template <typename RangeT, typename Char>
-struct formatter<RangeT, Char,
-                 enable_if_t<fmt::is_range<RangeT, Char>::value>> {
+template <typename T, typename Char>
+struct formatter<
+    T, Char,
+    enable_if_t<fmt::is_range<T, Char>::value
+// Workaround a bug in MSVC 2017 and earlier.
+#if !FMT_MSC_VER || FMT_MSC_VER >= 1927
+                &&
+                (has_formatter<detail::value_type<T>, format_context>::value ||
+                 detail::has_fallback_formatter<detail::value_type<T>,
+                                                format_context>::value)
+#endif
+                >> {
   formatting_range<Char> formatting;
 
   template <typename ParseContext>
@@ -257,8 +268,7 @@ struct formatter<RangeT, Char,
   }
 
   template <typename FormatContext>
-  typename FormatContext::iterator format(const RangeT& values,
-                                          FormatContext& ctx) {
+  typename FormatContext::iterator format(const T& values, FormatContext& ctx) {
     auto out = detail::copy(formatting.prefix, ctx.out());
     size_t i = 0;
     auto it = values.begin();

oss/fmt/src/format.cc

@@ -23,6 +23,36 @@ int format_float(char* buf, std::size_t size, const char* format, int precision,
   return precision < 0 ? snprintf_ptr(buf, size, format, value)
                        : snprintf_ptr(buf, size, format, precision, value);
 }
+
+template FMT_API dragonbox::decimal_fp<float> dragonbox::to_decimal(float x)
+    FMT_NOEXCEPT;
+template FMT_API dragonbox::decimal_fp<double> dragonbox::to_decimal(double x)
+    FMT_NOEXCEPT;
+
+// DEPRECATED! This function exists for ABI compatibility.
+template <typename Char>
+typename basic_format_context<std::back_insert_iterator<buffer<Char>>,
+                              Char>::iterator
+vformat_to(buffer<Char>& buf, basic_string_view<Char> format_str,
+           basic_format_args<basic_format_context<
+               std::back_insert_iterator<buffer<type_identity_t<Char>>>,
+               type_identity_t<Char>>>
+               args) {
+  using iterator = std::back_insert_iterator<buffer<char>>;
+  using context = basic_format_context<
+      std::back_insert_iterator<buffer<type_identity_t<Char>>>,
+      type_identity_t<Char>>;
+  auto out = iterator(buf);
+  format_handler<iterator, Char, context> h(out, format_str, args, {});
+  parse_format_string<false>(format_str, h);
+  return out;
+}
+template basic_format_context<std::back_insert_iterator<buffer<char>>,
+                              char>::iterator
+vformat_to(buffer<char>&, string_view,
+           basic_format_args<basic_format_context<
+               std::back_insert_iterator<buffer<type_identity_t<char>>>,
+               type_identity_t<char>>>);
 }  // namespace detail
 
 template struct FMT_INSTANTIATION_DEF_API detail::basic_data<void>;
@@ -44,9 +74,9 @@ template FMT_API char detail::decimal_point_impl(locale_ref);
 
 template FMT_API void detail::buffer<char>::append(const char*, const char*);
 
-template FMT_API FMT_BUFFER_CONTEXT(char)::iterator detail::vformat_to(
+template FMT_API void detail::vformat_to(
     detail::buffer<char>&, string_view,
-    basic_format_args<FMT_BUFFER_CONTEXT(char)>);
+    basic_format_args<FMT_BUFFER_CONTEXT(char)>, detail::locale_ref);
 
 template FMT_API int detail::snprintf_float(double, int, detail::float_specs,
                                             detail::buffer<char>&);

oss/fmt/src/os.cc

@@ -62,7 +62,7 @@ using RWResult = int;
 inline unsigned convert_rwcount(std::size_t count) {
   return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
 }
-#else
+#elif FMT_USE_FCNTL
 // Return type of read and write functions.
 using RWResult = ssize_t;
 
@@ -124,7 +124,8 @@ void detail::format_windows_error(detail::buffer<char>& out, int error_code,
       if (result != 0) {
         utf16_to_utf8 utf8_message;
         if (utf8_message.convert(system_message) == ERROR_SUCCESS) {
-          format_to(std::back_inserter(out), "{}: {}", message, utf8_message);
+          format_to(buffer_appender<char>(out), "{}: {}", message,
+                    utf8_message);
           return;
         }
         break;
@@ -288,12 +289,12 @@ void file::pipe(file& read_end, file& write_end) {
 }
 
 buffered_file file::fdopen(const char* mode) {
-  // Don't retry as fdopen doesn't return EINTR.
-  #if defined(__MINGW32__) && defined(_POSIX_)
+// Don't retry as fdopen doesn't return EINTR.
+#  if defined(__MINGW32__) && defined(_POSIX_)
   FILE* f = ::fdopen(fd_, mode);
-  #else
+#  else
   FILE* f = FMT_POSIX_CALL(fdopen(fd_, mode));
-  #endif
+#  endif
   if (!f)
     FMT_THROW(
         system_error(errno, "cannot associate stream with file descriptor"));
@@ -313,5 +314,9 @@ long getpagesize() {
   return size;
 #  endif
 }
+
+FMT_API void ostream::grow(size_t) {
+  if (this->size() == this->capacity()) flush();
+}
 #endif  // FMT_USE_FCNTL
 FMT_END_NAMESPACE

res/README.md

@@ -17,5 +17,5 @@ Please consult the [license](https://raw.githubusercontent.com/microsoft/cascadi
 
 ### Fonts Included
 
-* Cascadia Code, Cascadia Mono (2009.21)
-   * from microsoft/cascadia-code@32f84124db1970fa5d032f0fe9019e6922961beb
+* Cascadia Code, Cascadia Mono (2102.25)
+   * from microsoft/cascadia-code@911dc421f333e3b72b97381d16fee5b71eb48f04

res/terminal/Terminal.svg

@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg width="48" height="48" viewBox="0 0 48 48" fill="none" xmlns="http://www.w3.org/2000/svg">
 <path d="M0 13H16V6H2C0.9 6 0 6.9 0 8V13Z" fill="#CCCCCC"/>
 <path d="M32 6H16V13H32V6Z" fill="#999999"/>

res/terminal/Terminal_Dev_HC.svg

@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg width="48" height="48" viewBox="0 0 48 48" fill="none" xmlns="http://www.w3.org/2000/svg">
 <defs>
 <linearGradient id="foreground"><stop stop-color="#000000"/></linearGradient>

res/terminal/Terminal_HC.svg

@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg width="48" height="48" viewBox="0 0 48 48" fill="none" xmlns="http://www.w3.org/2000/svg">
 <defs>
 <linearGradient id="foreground"><stop stop-color="#000000"/></linearGradient>

samples/PixelShaders/Animate_breathe.hlsl

@@ -0,0 +1,42 @@
+// A simple animated shader that fades the terminal background back and forth between two colours
+
+// The terminal graphics as a texture
+Texture2D shaderTexture;
+SamplerState samplerState;
+
+// Terminal settings such as the resolution of the texture
+cbuffer PixelShaderSettings
+{
+    // The number of seconds since the pixel shader was enabled
+    float Time;
+    // UI Scale
+    float Scale;
+    // Resolution of the shaderTexture
+    float2 Resolution;
+    // Background color as rgba
+    float4 Background;
+};
+
+// pi and tau (2 * pi) are useful constants when using trigonometric functions
+#define TAU 6.28318530718
+
+// A pixel shader is a program that given a texture coordinate (tex) produces a color.
+// tex is an x,y tuple that ranges from 0,0 (top left) to 1,1 (bottom right).
+// Just ignore the pos parameter.
+float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
+{
+	// Read the color value at the current texture coordinate (tex)
+    float4 sample = shaderTexture.Sample(samplerState, tex);
+    
+    // The number of seconds the breathing effect should span
+    float duration = 5.0;
+    
+    float3 color1 = float3(0.3, 0.0, 0.5);  // indigo
+    float3 color2 = float3(0.1, 0.1, 0.44); // midnight blue
+    
+    // Set background colour based on the time
+    float4 backgroundColor = float4(lerp(color1, color2, 0.5 * cos(TAU / duration * Time) + 0.5), 1.0);
+    
+    // Draw the terminal graphics over the background
+    return lerp(backgroundColor, sample, sample.w);
+}

samples/PixelShaders/Animate_scan.hlsl

@@ -0,0 +1,45 @@
+// A simple animated shader that draws an inverted line that scrolls down the screen
+
+// The terminal graphics as a texture
+Texture2D shaderTexture;
+SamplerState samplerState;
+
+// Terminal settings such as the resolution of the texture
+cbuffer PixelShaderSettings
+{
+    // The number of seconds since the pixel shader was enabled
+    float Time;
+    // UI Scale
+    float Scale;
+    // Resolution of the shaderTexture
+    float2 Resolution;
+    // Background color as rgba
+    float4 Background;
+};
+
+// A pixel shader is a program that given a texture coordinate (tex) produces a color.
+// tex is an x,y tuple that ranges from 0,0 (top left) to 1,1 (bottom right).
+// Just ignore the pos parameter.
+float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
+{
+    // Read the color value at the current texture coordinate (tex)
+    float4 color = shaderTexture.Sample(samplerState, tex);
+    
+    // Here we spread the animation over 5 seconds. We use time modulo 5 because we want
+    // the timer to count to five repeatedly. We then divide the result by five again
+    // to get a value between 0.0 and 1.0, which maps to our texture coordinate.
+    float linePosition = Time % 5 / 5;
+    
+    // Since TEXCOORD ranges from 0.0 to 1.0, we need to divide 1.0 by the height of the
+    // texture to find out the size of a single pixel
+    float lineWidth = 1.0 / Resolution.y;
+	
+    // If the current texture coordinate is in the range of our line on the Y axis: 
+    if (tex.y > linePosition - lineWidth && tex.y < linePosition)
+    {
+        // Invert the sampled color
+        color.rgb = 1.0 - color.rgb;
+    }
+    
+    return color;
+}

samples/PixelShaders/Grayscale.hlsl

@@ -6,7 +6,7 @@ SamplerState samplerState;
 
 // Terminal settings such as the resolution of the texture
 cbuffer PixelShaderSettings {
-  // Time since pixel shader was enabled
+  // The number of seconds since the pixel shader was enabled
   float  Time;
   // UI Scale
   float  Scale;
@@ -16,8 +16,9 @@ cbuffer PixelShaderSettings {
   float4 Background;
 };
 
-// A pixel shader is a program that given a texture coordinate (tex) produces a color
-//  Just ignore the pos parameter
+// A pixel shader is a program that given a texture coordinate (tex) produces a color.
+// tex is an x,y tuple that ranges from 0,0 (top left) to 1,1 (bottom right).
+// Just ignore the pos parameter.
 float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
 {
     // Read the color value at the current texture coordinate (tex)

samples/PixelShaders/Invert.hlsl

@@ -6,7 +6,7 @@ SamplerState samplerState;
 
 // Terminal settings such as the resolution of the texture
 cbuffer PixelShaderSettings {
-  // Time since pixel shader was enabled
+  // The number of seconds since the pixel shader was enabled
   float  Time;
   // UI Scale
   float  Scale;
@@ -16,8 +16,9 @@ cbuffer PixelShaderSettings {
   float4 Background;
 };
 
-// A pixel shader is a program that given a texture coordinate (tex) produces a color
-//  Just ignore the pos parameter
+// A pixel shader is a program that given a texture coordinate (tex) produces a color.
+// tex is an x,y tuple that ranges from 0,0 (top left) to 1,1 (bottom right).
+// Just ignore the pos parameter.
 float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
 {
     // Read the color value at the current texture coordinate (tex)

samples/PixelShaders/README.md

@@ -20,7 +20,7 @@ SamplerState samplerState;
 
 // Terminal settings such as the resolution of the texture
 cbuffer PixelShaderSettings {
-  // Time since pixel shader was enabled
+  // The number of seconds since the pixel shader was enabled
   float  Time;
   // UI Scale
   float  Scale;
@@ -30,8 +30,9 @@ cbuffer PixelShaderSettings {
   float4 Background;
 };
 
-// A pixel shader is a program that given a texture coordinate (tex) produces a color
-//  Just ignore the pos parameter
+// A pixel shader is a program that given a texture coordinate (tex) produces a color.
+// tex is an x,y tuple that ranges from 0,0 (top left) to 1,1 (bottom right).
+// Just ignore the pos parameter.
 float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
 {
     // Read the color value at the current texture coordinate (tex)
@@ -49,16 +50,22 @@ float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
 Save this file as `C:\temp\invert.hlsl`, then update a profile with the setting:
 
 ```
-"experimental.pixelShaderEffect": "C:\\temp\\invert.hlsl"
+"experimental.pixelShaderPath": "C:\\temp\\invert.hlsl"
 ```
 
 Once the settings file is saved, open a terminal with the changed profile. It should now invert the colors of the screen!
 
+
+ Default Terminal | Inverted Terminal 
+---------|---------
+ ![Default Terminal](Screenshots/TerminalDefault.PNG) | ![Inverted Terminal](Screenshots/TerminalInvert.PNG) 
+
+
 If your shader fails to compile, the Terminal will display a warning dialog and ignore it temporarily. After fixing your shader, touch the `settings.json` file again, or open a new tab, and the Terminal will try loading the shader again.
 
 ## HLSL
 
-The language we use to write pixel shaders is called `HLSL`. It a `C`-like language, with some restrictions.You can't allocate memory, use pointers or recursion.
+The language we use to write pixel shaders is called `HLSL`. It's a `C`-like language, with some restrictions. You can't allocate memory, use pointers or recursion.
 What you get access to is computing power in the teraflop range on decently recent GPUs. This means writing real-time raytracers or other cool effects are in the realm of possibility.
 
 [shadertoy](https://shadertoy.com/) is a great site that show case what's possible with pixel shaders (albeit in `GLSL`). For example this [menger sponge](https://www.shadertoy.com/view/4scXzn). Converting from `GLSL` to `HLSL` isn't overly hard once you gotten the hang of it.
@@ -76,7 +83,7 @@ SamplerState samplerState;
 
 // Terminal settings such as the resolution of the texture
 cbuffer PixelShaderSettings {
-  // Time since pixel shader was enabled
+  // The number of seconds since the pixel shader was enabled
   float  Time;
   // UI Scale
   float  Scale;
@@ -86,8 +93,9 @@ cbuffer PixelShaderSettings {
   float4 Background;
 };
 
-// A pixel shader is a program that given a texture coordinate (tex) produces a color
-//  Just ignore the pos parameter
+// A pixel shader is a program that given a texture coordinate (tex) produces a color.
+// tex is an x,y tuple that ranges from 0,0 (top left) to 1,1 (bottom right).
+// Just ignore the pos parameter.
 float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
 {
     // Read the color value at the current texture coordinate (tex)
@@ -130,7 +138,83 @@ float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
 
 Once reloaded, it should show some retro raster bars in the background, with a drop shadow to make the text more readable.
 
+ ![Rasterbars](Screenshots/TerminalRasterbars.PNG)
+
 ## Retro Terminal Effect
 
-As a more complicated example, the Terminal's built-in `experimental.retroTerminalEffect` is included as the `Retro.hlsl` file in this directory. Feel free to modify and experiment!
+As a more complicated example, the Terminal's built-in `experimental.retroTerminalEffect` is included as the `Retro.hlsl` file in this directory. 
+
+![Retro](Screenshots/TerminalRetro.PNG)
+
+## Animated Effects
+
+You can use the `Time` value in the shader input settings to drive animated effects. `Time` is the number of seconds since the shader first loaded. Here’s a simple example with a line of inverted pixels that scrolls down the terminal (`Animate_scan.hlsl`):
+
+```hlsl
+float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
+{
+    // Read the color value at the current texture coordinate (tex)
+    float4 color = shaderTexture.Sample(samplerState, tex);
+    
+    // Here we spread the animation over 5 seconds. We use time modulo 5 because we want
+    // the timer to count to five repeatedly. We then divide the result by five again
+    // to get a value between 0.0 and 1.0, which maps to our texture coordinate.
+    float linePosition = Time % 5 / 5;
+    
+    // Since TEXCOORD ranges from 0.0 to 1.0, we need to divide 1.0 by the height of the
+    // texture to find out the size of a single pixel
+    float lineWidth = 1.0 / Resolution.y;
+	
+    // If the current texture coordinate is in the range of our line on the Y axis: 
+    if (tex.y > linePosition - lineWidth && tex.y < linePosition)
+    {
+        // Invert the sampled color
+        color.rgb = 1.0 - color.rgb;
+    }
+    
+    return color;
+}
+```
+What if we want an animation that goes backwards and forwards? In this example (`Animate_breathe.hlsl`), we'll make the background fade between two colours. Our `Time` value only ever goes up, so we need a way to generate a value that sweeps back and forth from `0.0` to `1.0`. Trigonometric functions like cosine are perfect for this and are very frequently used in shaders. 
+
+`cos()` outputs a value between `-1.0` and `1.0`. We can adjust the wave with the following formula:
+
+```
+a * cos(b * (x - c)) + d
+```
+
+Where `a` adjusts the amplitude, `b` adjusts the wavelength/frequency, `c` adjusts the offset along the x axis, and `d` adjusts the offset along the y axis. You can use a graphing calculator (such as the Windows Calculator) to help visualize the output and experiment:
+
+![Cosine](Screenshots/GraphCosine.png)
+
+As shown above, by halving the output and then adding `0.5`, we can shift the range of the function to `0.0` - `1.0`. Because `cos()` takes input in radians, if we multiply `x` (`Time`) by tau (`2*pi`), we are effectively setting the wavelength to `1.0`. 
+
+In other words, our full animation will be one second long. We can modify this duration by dividing tau by the number of seconds we want the animation to run for. In this case, we’ll go for five seconds.
+
+Finally we use linear interpolation to achieve our breathing effect by selecting a color between our two chosen colors based on the output from our cosine.
+
+```hlsl
+// pi and tau (2 * pi) are useful constants when using trigonometric functions
+#define TAU 6.28318530718
+
+float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
+{
+    // Read the color value at the current texture coordinate (tex)
+    float4 sample = shaderTexture.Sample(samplerState, tex);
+    
+    // The number of seconds the breathing effect should span
+    float duration = 5.0;
+    
+    float3 color1 = float3(0.3, 0.0, 0.5);  // indigo
+    float3 color2 = float3(0.1, 0.1, 0.44); // midnight blue
+    
+    // Set background colour based on the time
+    float4 backgroundColor = float4(lerp(color1, color2, 0.5 * cos(TAU / duration * Time) + 0.5), 1.0);
+    
+    // Draw the terminal graphics over the background
+    return lerp(backgroundColor, sample, sample.w);
+}
+```
+
+Feel free to modify and experiment!
 

samples/PixelShaders/Rasterbars.hlsl

@@ -6,7 +6,7 @@ SamplerState samplerState;
 
 // Terminal settings such as the resolution of the texture
 cbuffer PixelShaderSettings {
-  // Time since pixel shader was enabled
+  // The number of seconds since the pixel shader was enabled
   float  Time;
   // UI Scale
   float  Scale;
@@ -16,8 +16,9 @@ cbuffer PixelShaderSettings {
   float4 Background;
 };
 
-// A pixel shader is a program that given a texture coordinate (tex) produces a color
-//  Just ignore the pos parameter
+// A pixel shader is a program that given a texture coordinate (tex) produces a color.
+// tex is an x,y tuple that ranges from 0,0 (top left) to 1,1 (bottom right).
+// Just ignore the pos parameter.
 float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
 {
     // Read the color value at the current texture coordinate (tex)

src/buffer/out/AttrRow.cpp

@@ -4,30 +4,6 @@
 #include "precomp.h"
 #include "AttrRow.hpp"
 
-// Routine Description:
-// - constructor
-// Arguments:
-// - cchRowWidth - the length of the default text attribute
-// - attr - the default text attribute
-// Return Value:
-// - constructed object
-// Note: will throw exception if unable to allocate memory for text attribute storage
-ATTR_ROW::ATTR_ROW(const UINT cchRowWidth, const TextAttribute attr)
-{
-    _list.push_back(TextAttributeRun(cchRowWidth, attr));
-    _cchRowWidth = cchRowWidth;
-}
-
-// Routine Description:
-// - Sets all properties of the ATTR_ROW to default values
-// Arguments:
-// - attr - The default text attributes to use on text in this row.
-void ATTR_ROW::Reset(const TextAttribute attr)
-{
-    _list.clear();
-    _list.push_back(TextAttributeRun(_cchRowWidth, attr));
-}
-
 // Routine Description:
 // - Takes an existing row of attributes, and changes the length so that it fills the NewWidth.
 //     If the new size is bigger, then the last attr is extended to fill the NewWidth.
@@ -39,46 +15,12 @@ void ATTR_ROW::Reset(const TextAttribute attr)
 // - <none>, throws exceptions on failures.
 void ATTR_ROW::Resize(const size_t newWidth)
 {
-    THROW_HR_IF(E_INVALIDARG, 0 == newWidth);
+    mybase::resize(gsl::narrow<UINT>(newWidth));
+}
 
-    // Easy case. If the new row is longer, increase the length of the last run by how much new space there is.
-    if (newWidth > _cchRowWidth)
-    {
-        // Get the attribute that covers the final column of old width.
-        const auto runPos = FindAttrIndex(_cchRowWidth - 1, nullptr);
-        auto& run = _list.at(runPos);
-
-        // Extend its length by the additional columns we're adding.
-        run.SetLength(run.GetLength() + newWidth - _cchRowWidth);
-
-        // Store that the new total width we represent is the new width.
-        _cchRowWidth = newWidth;
-    }
-    // harder case: new row is shorter.
-    else
-    {
-        // Get the attribute that covers the final column of the new width
-        size_t CountOfAttr = 0;
-        const auto runPos = FindAttrIndex(newWidth - 1, &CountOfAttr);
-        auto& run = _list.at(runPos);
-
-        // CountOfAttr was given to us as "how many columns left from this point forward are covered by the returned run"
-        // So if the original run was B5 covering a 5 size OldWidth and we have a NewWidth of 3
-        // then when we called FindAttrIndex, it returned the B5 as the pIndexedRun and a 2 for how many more segments it covers
-        // after and including the 3rd column.
-        // B5-2 = B3, which is what we desire to cover the new 3 size buffer.
-        run.SetLength(run.GetLength() - CountOfAttr + 1);
-
-        // Store that the new total width we represent is the new width.
-        _cchRowWidth = newWidth;
-
-        // Erase segments after the one we just updated.
-        _list.erase(_list.cbegin() + runPos + 1, _list.cend());
-
-        // NOTE: Under some circumstances here, we have leftover run segments in memory or blank run segments
-        // in memory. We're not going to waste time redimensioning the array in the heap. We're just noting that the useful
-        // portions of it have changed.
-    }
+void ATTR_ROW::Reset(const TextAttribute attr)
+{
+    mybase::fill(attr);
 }
 
 // Routine Description:
@@ -91,7 +33,7 @@ void ATTR_ROW::Resize(const size_t newWidth)
 // - will throw on error
 TextAttribute ATTR_ROW::GetAttrByColumn(const size_t column) const
 {
-    return GetAttrByColumn(column, nullptr);
+    return mybase::at(gsl::narrow<UINT>(column));
 }
 
 // Routine Description:
@@ -106,87 +48,24 @@ TextAttribute ATTR_ROW::GetAttrByColumn(const size_t column) const
 TextAttribute ATTR_ROW::GetAttrByColumn(const size_t column,
                                         size_t* const pApplies) const
 {
-    THROW_HR_IF(E_INVALIDARG, column >= _cchRowWidth);
-    const auto runPos = FindAttrIndex(column, pApplies);
-    return _list.at(runPos).GetAttributes();
-}
-
-// Routine Description:
-// - reports how many runs we have stored (to be used for some optimizations
-// Return Value:
-// - Count of runs. 1 means we have 1 color to represent the entire row.
-size_t ATTR_ROW::GetNumberOfRuns() const noexcept
-{
-    return _list.size();
-}
-
-// Routine Description:
-// - This routine finds the nth attribute in this ATTR_ROW.
-// Arguments:
-// - index - which attribute to find
-// - applies - on output, contains corrected length of indexed attr.
-//             for example, if the attribute string was { 5, BLUE } and the requested
-//             index was 3, CountOfAttr would be 2.
-// Return Value:
-// - const reference to attribute run object
-size_t ATTR_ROW::FindAttrIndex(const size_t index, size_t* const pApplies) const
-{
-    FAIL_FAST_IF(!(index < _cchRowWidth)); // The requested index cannot be longer than the total length described by this set of Attrs.
-
-    size_t cTotalLength = 0;
-
-    FAIL_FAST_IF(!(_list.size() > 0)); // There should be a non-zero and positive number of items in the array.
-
-    // Scan through the internal array from position 0 adding up the lengths that each attribute applies to
-    auto runPos = _list.cbegin();
-    do
-    {
-        cTotalLength += runPos->GetLength();
-
-        if (cTotalLength > index)
-        {
-            // If we've just passed up the requested index with the length we added, break early
-            break;
-        }
-
-        runPos++;
-    } while (runPos < _list.cend());
-
-    // we should have broken before falling out the while case.
-    // if we didn't break, then this ATTR_ROW wasn't filled with enough attributes for the entire row of characters
-    FAIL_FAST_IF(runPos >= _list.cend());
-
-    // The remaining iterator position is the position of the attribute that is applicable at the position requested (index)
-    // Calculate its remaining applicability if requested
-
-    // The length on which the found attribute applies is the total length seen so far minus the index we were searching for.
-    FAIL_FAST_IF(!(cTotalLength > index)); // The length of all attributes we counted up so far should be longer than the index requested or we'll underflow.
-
-    if (nullptr != pApplies)
-    {
-        const auto attrApplies = cTotalLength - index;
-        FAIL_FAST_IF(!(attrApplies > 0)); // An attribute applies for >0 characters
-        // MSFT: 17130145 - will restore this and add a better assert to catch the real issue.
-        //FAIL_FAST_IF(!(attrApplies <= _cchRowWidth)); // An attribute applies for a maximum of the total length available to us
-
-        *pApplies = attrApplies;
-    }
-
-    return runPos - _list.cbegin();
+    UINT applies = 0;
+    const auto attr = mybase::at(gsl::narrow<UINT>(column), applies);
+    *pApplies = applies;
+    return attr;
 }
 
 // Routine Description:
 // - Finds the hyperlink IDs present in this row and returns them
 // Return value:
-// - An unordered set containing the hyperlink IDs present in this row
-std::unordered_set<uint16_t> ATTR_ROW::GetHyperlinks()
+// - The hyperlink IDs present in this row
+std::vector<uint16_t> ATTR_ROW::GetHyperlinks()
 {
-    std::unordered_set<uint16_t> ids;
-    for (const auto& run : _list)
+    std::vector<uint16_t> ids;
+    for (const auto& run : *this)
     {
-        if (run.GetAttributes().IsHyperlink())
+        if (run.IsHyperlink())
         {
-            ids.emplace(run.GetAttributes().GetHyperlinkId());
+            ids.emplace_back(run.GetHyperlinkId());
         }
     }
     return ids;
@@ -201,10 +80,8 @@ std::unordered_set<uint16_t> ATTR_ROW::GetHyperlinks()
 // - <none>
 bool ATTR_ROW::SetAttrToEnd(const UINT iStart, const TextAttribute attr)
 {
-    size_t const length = _cchRowWidth - iStart;
-
-    const TextAttributeRun run(length, attr);
-    return SUCCEEDED(InsertAttrRuns({ &run, 1 }, iStart, _cchRowWidth - 1, _cchRowWidth));
+    mybase::fill(attr, iStart);
+    return true;
 }
 
 // Method Description:
@@ -217,13 +94,7 @@ bool ATTR_ROW::SetAttrToEnd(const UINT iStart, const TextAttribute attr)
 // - <none>
 void ATTR_ROW::ReplaceAttrs(const TextAttribute& toBeReplacedAttr, const TextAttribute& replaceWith) noexcept
 {
-    for (auto& run : _list)
-    {
-        if (run.GetAttributes() == toBeReplacedAttr)
-        {
-            run.SetAttributes(replaceWith);
-        }
-    }
+    mybase::replace(toBeReplacedAttr, replaceWith);
 }
 
 // Routine Description:
@@ -242,393 +113,12 @@ void ATTR_ROW::ReplaceAttrs(const TextAttribute& toBeReplacedAttr, const TextAtt
 //   otherwise STATUS_SUCCESS if we were successful.
 [[nodiscard]] HRESULT ATTR_ROW::InsertAttrRuns(const gsl::span<const TextAttributeRun> newAttrs,
                                                const size_t iStart,
-                                               const size_t iEnd,
-                                               const size_t cBufferWidth)
+                                               const size_t /*iEnd*/,
+                                               const size_t /*cBufferWidth*/)
+try
 {
-    // Definitions:
-    // Existing Run = The run length encoded color array we're already storing in memory before this was called.
-    // Insert Run = The run length encoded color array that someone is asking us to inject into our stored memory run.
-    // New Run = The run length encoded color array that we have to allocate and rebuild to store internally
-    //           which will replace Existing Run at the end of this function.
-    // Example:
-    // cBufferWidth = 10.
-    // Existing Run: R3 -> G5 -> B2
-    // Insert Run: Y1 -> N1 at iStart = 5 and iEnd = 6
-    //            (rgInsertAttrs is a 2 length array with Y1->N1 in it and cInsertAttrs = 2)
-    // Final Run: R3 -> G2 -> Y1 -> N1 -> G1 -> B2
-
-    // We'll need to know what the last valid column is for some calculations versus iEnd
-    // because iEnd is specified to us as an inclusive index value.
-    // Do the -1 math here now so we don't have to have -1s scattered all over this function.
-    const size_t iLastBufferCol = cBufferWidth - 1;
-
-    // If the insertion size is 1, do some pre-processing to
-    // see if we can get this done quickly.
-    if (newAttrs.size() == 1)
-    {
-        // Get the new color attribute we're trying to apply
-        const TextAttribute NewAttr = til::at(newAttrs, 0).GetAttributes();
-
-        // If the existing run was only 1 element...
-        // ...and the new color is the same as the old, we don't have to do anything and can exit quick.
-        if (_list.size() == 1 && _list.at(0).GetAttributes() == NewAttr)
-        {
-            return S_OK;
-        }
-        // .. otherwise if we internally have a list of 2 or more and we're about to insert a single color
-        // it's possible that we just walk left-to-right through the row and find a quick exit.
-        else if (iStart >= 0 && iStart == iEnd)
-        {
-            // First we try to find the run where the insertion happens, using lowerBound and upperBound to track
-            // where we are currently at.
-            const auto begin = _list.begin();
-            size_t lowerBound = 0;
-            size_t upperBound = 0;
-            for (size_t i = 0; i < _list.size(); i++)
-            {
-                const auto curr = begin + i;
-                upperBound += curr->GetLength();
-
-                if (iStart >= lowerBound && iStart < upperBound)
-                {
-                    // The run that we try to insert into has the same color as the new one.
-                    // e.g.
-                    // AAAAABBBBBBBCCC
-                    //       ^
-                    // AAAAABBBBBBBCCC
-                    //
-                    // 'B' is the new color and '^' represents where iStart is. We don't have to
-                    // do anything.
-                    if (curr->GetAttributes() == NewAttr)
-                    {
-                        return S_OK;
-                    }
-
-                    // If the current run has length of exactly one, we can simply change the attribute
-                    // of the current run.
-                    // e.g.
-                    // AAAAABCCCCCCCCC
-                    //      ^
-                    // AAAAADCCCCCCCCC
-                    //
-                    // Here 'D' is the new color.
-                    if (curr->GetLength() == 1)
-                    {
-                        curr->SetAttributes(NewAttr);
-                        return S_OK;
-                    }
-
-                    // If the insertion happens at current run's lower boundary...
-                    if (iStart == lowerBound && i > 0)
-                    {
-                        const auto prev = std::prev(curr, 1);
-                        // ... and the previous run has the same color as the new one, we can
-                        // just adjust the counts in the existing two elements in our internal list.
-                        // e.g.
-                        // AAAAABBBBBBBCCC
-                        //      ^
-                        // AAAAAABBBBBBCCC
-                        //
-                        // Here 'A' is the new color.
-                        if (NewAttr == prev->GetAttributes())
-                        {
-                            prev->IncrementLength();
-                            curr->DecrementLength();
-
-                            // If we just reduced the right half to zero, just erase it out of the list.
-                            if (curr->GetLength() == 0)
-                            {
-                                _list.erase(curr);
-                            }
-
-                            return S_OK;
-                        }
-                    }
-
-                    // If the insertion happens at current run's upper boundary...
-                    if (iStart == upperBound - 1 && i + 1 < _list.size())
-                    {
-                        // ...then let's try our luck with the next run if possible. This is basically the opposite
-                        // of what we did with the previous run.
-                        // e.g.
-                        // AAAAAABBBBBBCCC
-                        //      ^
-                        // AAAAABBBBBBBCCC
-                        //
-                        // Here 'B' is the new color.
-                        const auto next = std::next(curr, 1);
-                        if (NewAttr == next->GetAttributes())
-                        {
-                            curr->DecrementLength();
-                            next->IncrementLength();
-
-                            if (curr->GetLength() == 0)
-                            {
-                                _list.erase(curr);
-                            }
-
-                            return S_OK;
-                        }
-                    }
-                }
-
-                // Advance one run in the _list.
-                lowerBound = upperBound;
-
-                // The lowerBound is larger than iStart, which means we fail to find an early exit at the run
-                // where the insertion happens. We can just break out.
-                if (lowerBound > iStart)
-                {
-                    break;
-                }
-            }
-        }
-    }
-
-    // If we're about to cover the entire existing run with a new one, we can also make an optimization.
-    if (iStart == 0 && iEnd == iLastBufferCol)
-    {
-        // Just dump what we're given over what we have and call it a day.
-        _list.assign(newAttrs.begin(), newAttrs.end());
-
-        return S_OK;
-    }
-
-    // In the worst case scenario, we will need a new run that is the length of
-    // The existing run in memory + The new run in memory + 1.
-    // This worst case occurs when we inject a new item in the middle of an existing run like so
-    // Existing R3->B5->G2, Insertion Y2 starting at 5 (in the middle of the B5)
-    // becomes R3->B2->Y2->B1->G2.
-    // The original run was 3 long. The insertion run was 1 long. We need 1 more for the
-    // fact that an existing piece of the run was split in half (to hold the latter half).
-    const size_t cNewRun = _list.size() + newAttrs.size() + 1;
-    std::vector<TextAttributeRun> newRun;
-    newRun.reserve(cNewRun);
-
-    // We will start analyzing from the beginning of our existing run.
-    // Use some pointers to keep track of where we are in walking through our runs.
-
-    // Get the existing run that we'll be updating/manipulating.
-    const auto existingRun = _list.begin();
-    auto pExistingRunPos = existingRun;
-    const auto pExistingRunEnd = _list.end();
-    auto pInsertRunPos = newAttrs.begin();
-    size_t cInsertRunRemaining = newAttrs.size();
-    size_t iExistingRunCoverage = 0;
-
-    // Copy the existing run into the new buffer up to the "start index" where the new run will be injected.
-    // If the new run starts at 0, we have nothing to copy from the beginning.
-    if (iStart != 0)
-    {
-        // While we're less than the desired insertion position...
-        while (iExistingRunCoverage < iStart)
-        {
-            // Add up how much length we can cover by copying an item from the existing run.
-            iExistingRunCoverage += pExistingRunPos->GetLength();
-
-            // Copy it to the new run buffer and advance both pointers.
-            newRun.push_back(*pExistingRunPos++);
-        }
-
-        // When we get to this point, we've copied full segments from the original existing run
-        // into our new run buffer. We will have 1 or more full segments of color attributes and
-        // we MIGHT have to cut the last copied segment's length back depending on where the inserted
-        // attributes will fall in the final/new run.
-        // Some examples:
-        // - Starting with the original string R3 -> G5 -> B2
-        // - 1. If the insertion is Y5 at start index 3
-        //      We are trying to get a result/final/new run of R3 -> Y5 -> B2.
-        //      We just copied R3 to the new destination buffer and we cang skip down and start inserting the new attrs.
-        // - 2. If the insertion is Y3 at start index 5
-        //      We are trying to get a result/final/new run of R3 -> G2 -> Y3 -> B2.
-        //      We just copied R3 -> G5 to the new destination buffer with the code above.
-        //      But the insertion is going to cut out some of the length of the G5.
-        //      We need to fix this up below so it says G2 instead to leave room for the Y3 to fit in
-        //      the new/final run.
-
-        // Fetch out the length so we can fix it up based on the below conditions.
-        size_t length = newRun.back().GetLength();
-
-        // If we've covered more cells already than the start of the attributes to be inserted...
-        if (iExistingRunCoverage > iStart)
-        {
-            // ..then subtract some of the length of the final cell we copied.
-            // We want to take remove the difference in distance between the cells we've covered in the new
-            // run and the insertion point.
-            // (This turns G5 into G2 from Example 2 just above)
-            length -= (iExistingRunCoverage - iStart);
-        }
-
-        // Now we're still on that "last cell copied" into the new run.
-        // If the color of that existing copied cell matches the color of the first segment
-        // of the run we're about to insert, we can just increment the length to extend the coverage.
-        if (newRun.back().GetAttributes() == pInsertRunPos->GetAttributes())
-        {
-            length += pInsertRunPos->GetLength();
-
-            // Since the color matched, we have already "used up" part of the insert run
-            // and can skip it in our big "memcopy" step below that will copy the bulk of the insert run.
-            cInsertRunRemaining--;
-            pInsertRunPos++;
-        }
-
-        // We're done manipulating the length. Store it back.
-        newRun.back().SetLength(length);
-    }
-
-    // Bulk copy the majority (or all, depending on circumstance) of the insert run into the final run buffer.
-    std::copy_n(pInsertRunPos, cInsertRunRemaining, std::back_inserter(newRun));
-
-    // We're technically done with the insert run now and have 0 remaining, but won't bother updating its pointers
-    // and counts any further because we won't use them.
-
-    // Now we need to move our pointer for the original existing run forward and update our counts
-    // on how many cells we could have copied from the source before finishing off the new run.
-    while (iExistingRunCoverage <= iEnd)
-    {
-        FAIL_FAST_IF(!(pExistingRunPos != pExistingRunEnd));
-        iExistingRunCoverage += pExistingRunPos->GetLength();
-        pExistingRunPos++;
-    }
-
-    // If we still have original existing run cells remaining, copy them into the final new run.
-    if (pExistingRunPos != pExistingRunEnd || iExistingRunCoverage != (iEnd + 1))
-    {
-        // We advanced the existing run pointer and its count to on or past the end of what the insertion run filled in.
-        // If this ended up being past the end of what the insertion run covers, we have to account for the cells after
-        // the insertion run but before the next piece of the original existing run.
-        // The example in this case is if we had...
-        // Existing Run = R3 -> G5 -> B2 -> X5
-        // Insert Run = Y2 @ iStart = 7 and iEnd = 8
-        // ... then at this point in time, our states would look like...
-        // New Run so far = R3 -> G4 -> Y2
-        // Existing Run Pointer is at X5
-        // Existing run coverage count at 3 + 5 + 2 = 10.
-        // However, in order to get the final desired New Run
-        //   (which is R3 -> G4 -> Y2 -> B1 -> X5)
-        //   we would need to grab a piece of that B2 we already skipped past.
-        // iExistingRunCoverage = 10. iEnd = 8. iEnd+1 = 9. 10 > 9. So we skipped something.
-        if (iExistingRunCoverage > (iEnd + 1))
-        {
-            // Back up the existing run pointer so we can grab the piece we skipped.
-            pExistingRunPos--;
-
-            // If the color matches what's already in our run, just increment the count value.
-            // This case is slightly off from the example above. This case is for if the B2 above was actually Y2.
-            // That Y2 from the existing run is the same color as the Y2 we just filled a few columns left in the final run
-            // so we can just adjust the final run's column count instead of adding another segment here.
-            if (newRun.back().GetAttributes() == pExistingRunPos->GetAttributes())
-            {
-                size_t length = newRun.back().GetLength();
-                length += (iExistingRunCoverage - (iEnd + 1));
-                newRun.back().SetLength(length);
-            }
-            else
-            {
-                // If the color didn't match, then we just need to copy the piece we skipped and adjust
-                // its length for the discrepancy in columns not yet covered by the final/new run.
-
-                // Move forward to a blank spot in the new run
-                newRun.emplace_back();
-
-                // Copy the existing run's color information to the new run
-                newRun.back().SetAttributes(pExistingRunPos->GetAttributes());
-
-                // Adjust the length of that copied color to cover only the reduced number of columns needed
-                // now that some have been replaced by the insert run.
-                newRun.back().SetLength(iExistingRunCoverage - (iEnd + 1));
-            }
-
-            // Now that we're done recovering a piece of the existing run we skipped, move the pointer forward again.
-            pExistingRunPos++;
-        }
-
-        // OK. In this case, we didn't skip anything. The end of the insert run fell right at a boundary
-        // in columns that was in the original existing run.
-        // However, the next piece of the original existing run might happen to have the same color attribute
-        // as the final piece of what we just copied.
-        // As an example...
-        // Existing Run = R3 -> G5 -> B2.
-        // Insert Run = B5 @ iStart = 3 and iEnd = 7
-        // New Run so far = R3 -> B5
-        // New Run desired when done = R3 -> B7
-        // Existing run pointer is on B2.
-        // We want to merge the 2 from the B2 into the B5 so we get B7.
-        else if (newRun.back().GetAttributes() == pExistingRunPos->GetAttributes())
-        {
-            // Add the value from the existing run into the current new run position.
-            size_t length = newRun.back().GetLength();
-            length += pExistingRunPos->GetLength();
-            newRun.back().SetLength(length);
-
-            // Advance the existing run position since we consumed its value and merged it in.
-            pExistingRunPos++;
-        }
-
-        // Now bulk copy any segments left in the original existing run
-        if (pExistingRunPos < pExistingRunEnd)
-        {
-            std::copy_n(pExistingRunPos, (pExistingRunEnd - pExistingRunPos), std::back_inserter(newRun));
-        }
-    }
-
-    // OK, phew. We're done. Now we just need to free the existing run and store the new run in its place.
-    _list.swap(newRun);
+    mybase::replace(iStart, mybase::npos, newAttrs.begin(), newAttrs.end());
 
     return S_OK;
 }
-
-// Routine Description:
-// - packs a vector of TextAttribute into a vector of TextAttributeRun
-// Arguments:
-// - attrs - text attributes to pack
-// Return Value:
-// - packed text attribute run
-std::vector<TextAttributeRun> ATTR_ROW::PackAttrs(const std::vector<TextAttribute>& attrs)
-{
-    std::vector<TextAttributeRun> runs;
-    if (attrs.empty())
-    {
-        return runs;
-    }
-    for (auto attr : attrs)
-    {
-        if (runs.empty() || runs.back().GetAttributes() != attr)
-        {
-            const TextAttributeRun run(1, attr);
-            runs.push_back(run);
-        }
-        else
-        {
-            runs.back().SetLength(runs.back().GetLength() + 1);
-        }
-    }
-    return runs;
-}
-
-ATTR_ROW::const_iterator ATTR_ROW::begin() const noexcept
-{
-    return AttrRowIterator(this);
-}
-
-ATTR_ROW::const_iterator ATTR_ROW::end() const noexcept
-{
-    return AttrRowIterator::CreateEndIterator(this);
-}
-
-ATTR_ROW::const_iterator ATTR_ROW::cbegin() const noexcept
-{
-    return AttrRowIterator(this);
-}
-
-ATTR_ROW::const_iterator ATTR_ROW::cend() const noexcept
-{
-    return AttrRowIterator::CreateEndIterator(this);
-}
-
-bool operator==(const ATTR_ROW& a, const ATTR_ROW& b) noexcept
-{
-    return (a._list.size() == b._list.size() &&
-            a._list.data() == b._list.data() &&
-            a._cchRowWidth == b._cchRowWidth);
-}
+CATCH_RETURN()

src/buffer/out/AttrRow.hpp

@@ -20,30 +20,27 @@ Revision History:
 
 #pragma once
 
-#include "TextAttributeRun.hpp"
-#include "AttrRowIterator.hpp"
+#include "til/rle.h"
 
-class ATTR_ROW final
+#include "TextAttributeRun.hpp"
+
+class ATTR_ROW final : public til::rle<TextAttribute, unsigned int>
 {
 public:
-    using const_iterator = typename AttrRowIterator;
+    using mybase = til::rle<TextAttribute, unsigned int>;
 
-    ATTR_ROW(const UINT cchRowWidth, const TextAttribute attr);
+    using const_iterator = mybase::const_iterator;
+    using const_reverse_iterator = mybase::const_reverse_iterator;
 
-    void Reset(const TextAttribute attr);
+    using mybase::mybase; // use base constructor
 
     TextAttribute GetAttrByColumn(const size_t column) const;
     TextAttribute GetAttrByColumn(const size_t column,
                                   size_t* const pApplies) const;
 
-    size_t GetNumberOfRuns() const noexcept;
+    std::vector<uint16_t> GetHyperlinks();
 
-    size_t FindAttrIndex(const size_t index,
-                         size_t* const pApplies) const;
-
-    std::unordered_set<uint16_t> GetHyperlinks();
-
-    bool SetAttrToEnd(const UINT iStart, const TextAttribute attr);
+    bool SetAttrToEnd(const unsigned int iStart, const TextAttribute attr);
     void ReplaceAttrs(const TextAttribute& toBeReplacedAttr, const TextAttribute& replaceWith) noexcept;
 
     void Resize(const size_t newWidth);
@@ -53,22 +50,19 @@ public:
                                          const size_t iEnd,
                                          const size_t cBufferWidth);
 
-    static std::vector<TextAttributeRun> PackAttrs(const std::vector<TextAttribute>& attrs);
+    using mybase::begin;
+    using mybase::cbegin;
+    using mybase::cend;
+    using mybase::end;
 
-    const_iterator begin() const noexcept;
-    const_iterator end() const noexcept;
+    using mybase::operator==;
 
-    const_iterator cbegin() const noexcept;
-    const_iterator cend() const noexcept;
-
-    friend bool operator==(const ATTR_ROW& a, const ATTR_ROW& b) noexcept;
-    friend class AttrRowIterator;
+    friend class ROW;
 
 private:
-    std::vector<TextAttributeRun> _list;
-    size_t _cchRowWidth;
+    void Reset(const TextAttribute attr);
 
 #ifdef UNIT_TESTING
-    friend class AttrRowTests;
+    friend class CommonState;
 #endif
 };

src/buffer/out/AttrRowIterator.cpp

@@ -39,19 +39,6 @@ bool AttrRowIterator::operator!=(const AttrRowIterator& it) const noexcept
     return !(*this == it);
 }
 
-AttrRowIterator& AttrRowIterator::operator++() noexcept
-{
-    _increment(1);
-    return *this;
-}
-
-AttrRowIterator AttrRowIterator::operator++(int) noexcept
-{
-    auto copy = *this;
-    _increment(1);
-    return copy;
-}
-
 AttrRowIterator& AttrRowIterator::operator+=(const ptrdiff_t& movement)
 {
     if (!_exceeded)
@@ -74,19 +61,6 @@ AttrRowIterator& AttrRowIterator::operator-=(const ptrdiff_t& movement)
     return this->operator+=(-movement);
 }
 
-AttrRowIterator& AttrRowIterator::operator--() noexcept
-{
-    _decrement(1);
-    return *this;
-}
-
-AttrRowIterator AttrRowIterator::operator--(int) noexcept
-{
-    auto copy = *this;
-    _decrement(1);
-    return copy;
-}
-
 const TextAttribute* AttrRowIterator::operator->() const
 {
     THROW_HR_IF(E_BOUNDS, _exceeded);

src/buffer/out/AttrRowIterator.hpp

@@ -38,20 +38,38 @@ public:
     bool operator==(const AttrRowIterator& it) const noexcept;
     bool operator!=(const AttrRowIterator& it) const noexcept;
 
-    AttrRowIterator& operator++() noexcept;
-    AttrRowIterator operator++(int) noexcept;
+    AttrRowIterator& operator++() noexcept
+    {
+        _increment(1);
+        return *this;
+    }
+    AttrRowIterator operator++(int) noexcept
+    {
+        auto copy = *this;
+        _increment(1);
+        return copy;
+    }
 
     AttrRowIterator& operator+=(const ptrdiff_t& movement);
     AttrRowIterator& operator-=(const ptrdiff_t& movement);
 
-    AttrRowIterator& operator--() noexcept;
-    AttrRowIterator operator--(int) noexcept;
+    AttrRowIterator& operator--() noexcept
+    {
+        _decrement(1);
+        return *this;
+    }
+    AttrRowIterator operator--(int) noexcept
+    {
+        auto copy = *this;
+        _decrement(1);
+        return copy;
+    }
 
     const TextAttribute* operator->() const;
     const TextAttribute& operator*() const;
 
 private:
-    std::vector<TextAttributeRun>::const_iterator _run;
+    boost::container::small_vector_base<TextAttributeRun>::const_iterator _run;
     const ATTR_ROW* _pAttrRow;
     size_t _currentAttributeIndex; // index of TextAttribute within the current TextAttributeRun
     bool _exceeded;

src/buffer/out/CharRow.cpp

@@ -15,57 +15,14 @@
 // Return Value:
 // - instantiated object
 // Note: will through if unable to allocate char/attribute buffers
-CharRow::CharRow(size_t rowWidth, ROW* const pParent) :
-    _wrapForced{ false },
-    _doubleBytePadded{ false },
+#pragma warning(push)
+#pragma warning(disable : 26447) // small_vector's constructor says it can throw but it should not given how we use it.  This suppresses this error for the AuditMode build.
+CharRow::CharRow(size_t rowWidth, ROW* const pParent) noexcept :
     _data(rowWidth, value_type()),
     _pParent{ FAIL_FAST_IF_NULL(pParent) }
 {
 }
-
-// Routine Description:
-// - Sets the wrap status for the current row
-// Arguments:
-// - wrapForced - True if the row ran out of space and we forced to wrap to the next row. False otherwise.
-// Return Value:
-// - <none>
-void CharRow::SetWrapForced(const bool wrapForced) noexcept
-{
-    _wrapForced = wrapForced;
-}
-
-// Routine Description:
-// - Gets the wrap status for the current row
-// Arguments:
-// - <none>
-// Return Value:
-// - True if the row ran out of space and we were forced to wrap to the next row. False otherwise.
-bool CharRow::WasWrapForced() const noexcept
-{
-    return _wrapForced;
-}
-
-// Routine Description:
-// - Sets the double byte padding for the current row
-// Arguments:
-// - fWrapWasForced - True if the row ran out of space for a double byte character and we padded out the row. False otherwise.
-// Return Value:
-// - <none>
-void CharRow::SetDoubleBytePadded(const bool doubleBytePadded) noexcept
-{
-    _doubleBytePadded = doubleBytePadded;
-}
-
-// Routine Description:
-// - Gets the double byte padding status for the current row.
-// Arguments:
-// - <none>
-// Return Value:
-// - True if the row didn't have space for a double byte character and we were padded out the row. False otherwise.
-bool CharRow::WasDoubleBytePadded() const noexcept
-{
-    return _doubleBytePadded;
-}
+#pragma warning(pop)
 
 // Routine Description:
 // - gets the size of the row, in glyph cells
@@ -90,9 +47,6 @@ void CharRow::Reset() noexcept
     {
         cell.Reset();
     }
-
-    _wrapForced = false;
-    _doubleBytePadded = false;
 }
 
 // Routine Description:
@@ -141,7 +95,7 @@ typename CharRow::const_iterator CharRow::cend() const noexcept
 // - The calculated left boundary of the internal string.
 size_t CharRow::MeasureLeft() const noexcept
 {
-    std::vector<value_type>::const_iterator it = _data.cbegin();
+    const_iterator it = _data.cbegin();
     while (it != _data.cend() && it->IsSpace())
     {
         ++it;
@@ -155,9 +109,9 @@ size_t CharRow::MeasureLeft() const noexcept
 // - <none>
 // Return Value:
 // - The calculated right boundary of the internal string.
-size_t CharRow::MeasureRight() const noexcept
+size_t CharRow::MeasureRight() const
 {
-    std::vector<value_type>::const_reverse_iterator it = _data.crbegin();
+    const_reverse_iterator it = _data.crbegin();
     while (it != _data.crend() && it->IsSpace())
     {
         ++it;

src/buffer/out/CharRow.hpp

@@ -49,27 +49,21 @@ class CharRow final
 public:
     using glyph_type = typename wchar_t;
     using value_type = typename CharRowCell;
-    using iterator = typename std::vector<value_type>::iterator;
-    using const_iterator = typename std::vector<value_type>::const_iterator;
+    using iterator = typename boost::container::small_vector_base<value_type>::iterator;
+    using const_iterator = typename boost::container::small_vector_base<value_type>::const_iterator;
+    using const_reverse_iterator = typename boost::container::small_vector_base<value_type>::const_reverse_iterator;
     using reference = typename CharRowCellReference;
 
-    CharRow(size_t rowWidth, ROW* const pParent);
+    CharRow(size_t rowWidth, ROW* const pParent) noexcept;
 
-    void SetWrapForced(const bool wrap) noexcept;
-    bool WasWrapForced() const noexcept;
-    void SetDoubleBytePadded(const bool doubleBytePadded) noexcept;
-    bool WasDoubleBytePadded() const noexcept;
     size_t size() const noexcept;
-    void Reset() noexcept;
     [[nodiscard]] HRESULT Resize(const size_t newSize) noexcept;
     size_t MeasureLeft() const noexcept;
-    size_t MeasureRight() const noexcept;
-    void ClearCell(const size_t column);
+    size_t MeasureRight() const;
     bool ContainsText() const noexcept;
     const DbcsAttribute& DbcsAttrAt(const size_t column) const;
     DbcsAttribute& DbcsAttrAt(const size_t column);
     void ClearGlyph(const size_t column);
-    std::wstring GetText() const;
 
     const DelimiterClass DelimiterClassAt(const size_t column, const std::wstring_view wordDelimiters) const;
 
@@ -80,9 +74,11 @@ public:
     // iterators
     iterator begin() noexcept;
     const_iterator cbegin() const noexcept;
+    const_iterator begin() const noexcept { return cbegin(); }
 
     iterator end() noexcept;
     const_iterator cend() const noexcept;
+    const_iterator end() const noexcept { return cend(); }
 
     UnicodeStorage& GetUnicodeStorage() noexcept;
     const UnicodeStorage& GetUnicodeStorage() const noexcept;
@@ -91,29 +87,21 @@ public:
     void UpdateParent(ROW* const pParent);
 
     friend CharRowCellReference;
-    friend constexpr bool operator==(const CharRow& a, const CharRow& b) noexcept;
+    friend class ROW;
+
+private:
+    void Reset() noexcept;
+    void ClearCell(const size_t column);
+    std::wstring GetText() const;
 
 protected:
-    // Occurs when the user runs out of text in a given row and we're forced to wrap the cursor to the next line
-    bool _wrapForced;
-
-    // Occurs when the user runs out of text to support a double byte character and we're forced to the next line
-    bool _doubleBytePadded;
-
     // storage for glyph data and dbcs attributes
-    std::vector<value_type> _data;
+    boost::container::small_vector<value_type, 120> _data;
 
     // ROW that this CharRow belongs to
     ROW* _pParent;
 };
 
-constexpr bool operator==(const CharRow& a, const CharRow& b) noexcept
-{
-    return (a._wrapForced == b._wrapForced &&
-            a._doubleBytePadded == b._doubleBytePadded &&
-            a._data == b._data);
-}
-
 template<typename InputIt1, typename InputIt2>
 void OverwriteColumns(InputIt1 startChars, InputIt1 endChars, InputIt2 startAttrs, CharRow::iterator outIt)
 {

src/buffer/out/CharRowCell.cpp

@@ -8,18 +8,6 @@
 // default glyph value, used for resetting the character data portion of a cell
 static constexpr wchar_t DefaultValue = UNICODE_SPACE;
 
-CharRowCell::CharRowCell() noexcept :
-    _wch{ DefaultValue },
-    _attr{}
-{
-}
-
-CharRowCell::CharRowCell(const wchar_t wch, const DbcsAttribute attr) noexcept :
-    _wch{ wch },
-    _attr{ attr }
-{
-}
-
 // Routine Description:
 // - "erases" the glyph. really sets it back to the default "empty" value
 void CharRowCell::EraseChars() noexcept

src/buffer/out/CharRowCell.hpp

@@ -17,6 +17,7 @@ Author(s):
 #pragma once
 
 #include "DbcsAttribute.hpp"
+#include "unicode.hpp"
 
 #if (defined(_M_IX86) || defined(_M_AMD64))
 // currently CharRowCell's fields use 3 bytes of memory, leaving the 4th byte in unused. this leads
@@ -27,8 +28,13 @@ Author(s):
 class CharRowCell final
 {
 public:
-    CharRowCell() noexcept;
-    CharRowCell(const wchar_t wch, const DbcsAttribute attr) noexcept;
+    CharRowCell() noexcept = default;
+    CharRowCell(const wchar_t wch, const DbcsAttribute attr) noexcept
+        :
+        _wch(wch),
+        _attr(attr)
+    {
+    }
 
     void EraseChars() noexcept;
     void Reset() noexcept;
@@ -44,8 +50,8 @@ public:
     friend constexpr bool operator==(const CharRowCell& a, const CharRowCell& b) noexcept;
 
 private:
-    wchar_t _wch;
-    DbcsAttribute _attr;
+    wchar_t _wch{ UNICODE_SPACE };
+    DbcsAttribute _attr{};
 };
 
 #if (defined(_M_IX86) || defined(_M_AMD64))

src/buffer/out/CharRowCellReference.hpp

@@ -32,8 +32,8 @@ public:
     }
 
     ~CharRowCellReference() = default;
-    CharRowCellReference(const CharRowCellReference&) = default;
-    CharRowCellReference(CharRowCellReference&&) = default;
+    CharRowCellReference(const CharRowCellReference&) noexcept = default;
+    CharRowCellReference(CharRowCellReference&&) noexcept = default;
 
     void operator=(const CharRowCellReference&) = delete;
     void operator=(CharRowCellReference&&) = delete;

src/buffer/out/LineRendition.hpp

@@ -0,0 +1,36 @@
+/*++
+Copyright (c) Microsoft Corporation
+Licensed under the MIT license.
+
+Module Name:
+- LineRendition.hpp
+
+Abstract:
+- Enumerated type for the VT line rendition attribute. This determines the
+  width and height scaling with which each line is rendered.
+
+--*/
+
+#pragma once
+
+enum class LineRendition
+{
+    SingleWidth,
+    DoubleWidth,
+    DoubleHeightTop,
+    DoubleHeightBottom
+};
+
+constexpr SMALL_RECT ScreenToBufferLine(const SMALL_RECT& line, const LineRendition lineRendition)
+{
+    // Use shift right to quickly divide the Left and Right by 2 for double width lines.
+    const auto scale = lineRendition == LineRendition::SingleWidth ? 0 : 1;
+    return { line.Left >> scale, line.Top, line.Right >> scale, line.Bottom };
+}
+
+constexpr SMALL_RECT BufferToScreenLine(const SMALL_RECT& line, const LineRendition lineRendition)
+{
+    // Use shift left to quickly multiply the Left and Right by 2 for double width lines.
+    const SHORT scale = lineRendition == LineRendition::SingleWidth ? 0 : 1;
+    return { line.Left << scale, line.Top, (line.Right << scale) + scale, line.Bottom };
+}

src/buffer/out/Row.cpp

@@ -16,50 +16,18 @@
 // - pParent - the text buffer that this row belongs to
 // Return Value:
 // - constructed object
-ROW::ROW(const SHORT rowId, const short rowWidth, const TextAttribute fillAttribute, TextBuffer* const pParent) :
+ROW::ROW(const SHORT rowId, const unsigned short rowWidth, const TextAttribute fillAttribute, TextBuffer* const pParent) noexcept :
     _id{ rowId },
-    _rowWidth{ gsl::narrow<size_t>(rowWidth) },
-    _charRow{ gsl::narrow<size_t>(rowWidth), this },
-    _attrRow{ gsl::narrow<UINT>(rowWidth), fillAttribute },
+    _rowWidth{ rowWidth },
+    _charRow{ rowWidth, this },
+    _attrRow{ rowWidth, fillAttribute },
+    _lineRendition{ LineRendition::SingleWidth },
+    _wrapForced{ false },
+    _doubleBytePadded{ false },
     _pParent{ pParent }
 {
 }
 
-size_t ROW::size() const noexcept
-{
-    return _rowWidth;
-}
-
-const CharRow& ROW::GetCharRow() const noexcept
-{
-    return _charRow;
-}
-
-CharRow& ROW::GetCharRow() noexcept
-{
-    return _charRow;
-}
-
-const ATTR_ROW& ROW::GetAttrRow() const noexcept
-{
-    return _attrRow;
-}
-
-ATTR_ROW& ROW::GetAttrRow() noexcept
-{
-    return _attrRow;
-}
-
-SHORT ROW::GetId() const noexcept
-{
-    return _id;
-}
-
-void ROW::SetId(const SHORT id) noexcept
-{
-    _id = id;
-}
-
 // Routine Description:
 // - Sets all properties of the ROW to default values
 // Arguments:
@@ -68,6 +36,9 @@ void ROW::SetId(const SHORT id) noexcept
 // - <none>
 bool ROW::Reset(const TextAttribute Attr)
 {
+    _lineRendition = LineRendition::SingleWidth;
+    _wrapForced = false;
+    _doubleBytePadded = false;
     _charRow.Reset();
     try
     {
@@ -87,7 +58,7 @@ bool ROW::Reset(const TextAttribute Attr)
 // - width - the new width, in cells
 // Return Value:
 // - S_OK if successful, otherwise relevant error
-[[nodiscard]] HRESULT ROW::Resize(const size_t width)
+[[nodiscard]] HRESULT ROW::Resize(const unsigned short width)
 {
     RETURN_IF_FAILED(_charRow.Resize(width));
     try
@@ -113,25 +84,6 @@ void ROW::ClearColumn(const size_t column)
     _charRow.ClearCell(column);
 }
 
-// Routine Description:
-// - gets the text of the row as it would be shown on the screen
-// Return Value:
-// - wstring containing text for the row
-std::wstring ROW::GetText() const
-{
-    return _charRow.GetText();
-}
-
-RowCellIterator ROW::AsCellIter(const size_t startIndex) const
-{
-    return AsCellIter(startIndex, size() - startIndex);
-}
-
-RowCellIterator ROW::AsCellIter(const size_t startIndex, const size_t count) const
-{
-    return RowCellIterator(*this, startIndex, count);
-}
-
 UnicodeStorage& ROW::GetUnicodeStorage() noexcept
 {
     return _pParent->GetUnicodeStorage();
@@ -213,7 +165,7 @@ OutputCellIterator ROW::WriteCells(OutputCellIterator it, const size_t index, co
                 else if (fillingLastColumn && it->DbcsAttr().IsLeading())
                 {
                     _charRow.ClearCell(currentIndex);
-                    _charRow.SetDoubleBytePadded(true);
+                    SetDoubleBytePadded(true);
                 }
                 // Otherwise, copy the data given and increment the iterator.
                 else
@@ -231,7 +183,7 @@ OutputCellIterator ROW::WriteCells(OutputCellIterator it, const size_t index, co
                 if (wrap.has_value() && fillingLastColumn)
                 {
                     // set wrap status on the row to parameter's value.
-                    _charRow.SetWrapForced(wrap.value());
+                    SetWrapForced(*wrap);
                 }
             }
             else

src/buffer/out/Row.hpp

@@ -21,10 +21,10 @@ Revision History:
 #pragma once
 
 #include "AttrRow.hpp"
+#include "LineRendition.hpp"
 #include "OutputCell.hpp"
 #include "OutputCellIterator.hpp"
 #include "CharRow.hpp"
-#include "RowCellIterator.hpp"
 #include "UnicodeStorage.hpp"
 
 class TextBuffer;
@@ -32,52 +32,63 @@ class TextBuffer;
 class ROW final
 {
 public:
-    ROW(const SHORT rowId, const short rowWidth, const TextAttribute fillAttribute, TextBuffer* const pParent);
+    ROW(const SHORT rowId, const unsigned short rowWidth, const TextAttribute fillAttribute, TextBuffer* const pParent)
+    noexcept;
 
-    size_t size() const noexcept;
+    size_t size() const noexcept { return _rowWidth; }
 
-    const CharRow& GetCharRow() const noexcept;
-    CharRow& GetCharRow() noexcept;
+    void SetWrapForced(const bool wrap) noexcept { _wrapForced = wrap; }
+    bool WasWrapForced() const noexcept { return _wrapForced; }
 
-    const ATTR_ROW& GetAttrRow() const noexcept;
-    ATTR_ROW& GetAttrRow() noexcept;
+    void SetDoubleBytePadded(const bool doubleBytePadded) noexcept { _doubleBytePadded = doubleBytePadded; }
+    bool WasDoubleBytePadded() const noexcept { return _doubleBytePadded; }
 
-    SHORT GetId() const noexcept;
-    void SetId(const SHORT id) noexcept;
+    const CharRow& GetCharRow() const noexcept { return _charRow; }
+    CharRow& GetCharRow() noexcept { return _charRow; }
+
+    const ATTR_ROW& GetAttrRow() const noexcept { return _attrRow; }
+    ATTR_ROW& GetAttrRow() noexcept { return _attrRow; }
+
+    LineRendition GetLineRendition() const noexcept { return _lineRendition; }
+    void SetLineRendition(const LineRendition lineRendition) noexcept { _lineRendition = lineRendition; }
+
+    SHORT GetId() const noexcept { return _id; }
+    void SetId(const SHORT id) noexcept { _id = id; }
 
     bool Reset(const TextAttribute Attr);
-    [[nodiscard]] HRESULT Resize(const size_t width);
+    [[nodiscard]] HRESULT Resize(const unsigned short width);
 
     void ClearColumn(const size_t column);
-    std::wstring GetText() const;
-
-    RowCellIterator AsCellIter(const size_t startIndex) const;
-    RowCellIterator AsCellIter(const size_t startIndex, const size_t count) const;
+    std::wstring GetText() const { return _charRow.GetText(); }
 
     UnicodeStorage& GetUnicodeStorage() noexcept;
     const UnicodeStorage& GetUnicodeStorage() const noexcept;
 
     OutputCellIterator WriteCells(OutputCellIterator it, const size_t index, const std::optional<bool> wrap = std::nullopt, std::optional<size_t> limitRight = std::nullopt);
 
-    friend bool operator==(const ROW& a, const ROW& b) noexcept;
-
 #ifdef UNIT_TESTING
+    friend constexpr bool operator==(const ROW& a, const ROW& b) noexcept;
     friend class RowTests;
 #endif
 
 private:
     CharRow _charRow;
     ATTR_ROW _attrRow;
+    LineRendition _lineRendition;
     SHORT _id;
-    size_t _rowWidth;
+    unsigned short _rowWidth;
+    // Occurs when the user runs out of text in a given row and we're forced to wrap the cursor to the next line
+    bool _wrapForced;
+    // Occurs when the user runs out of text to support a double byte character and we're forced to the next line
+    bool _doubleBytePadded;
     TextBuffer* _pParent; // non ownership pointer
 };
 
-inline bool operator==(const ROW& a, const ROW& b) noexcept
+#ifdef UNIT_TESTING
+constexpr bool operator==(const ROW& a, const ROW& b) noexcept
 {
-    return (a._charRow == b._charRow &&
-            a._attrRow == b._attrRow &&
-            a._rowWidth == b._rowWidth &&
-            a._pParent == b._pParent &&
+    // comparison is only used in the tests; this should suffice.
+    return (a._pParent == b._pParent &&
             a._id == b._id);
 }
+#endif

src/buffer/out/RowCellIterator.cpp

@@ -1,110 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT license.
-
-#include "precomp.h"
-
-#include "RowCellIterator.hpp"
-#include "Row.hpp"
-
-#include "../../types/inc/convert.hpp"
-#include "../../types/inc/Utf16Parser.hpp"
-
-RowCellIterator::RowCellIterator(const ROW& row, const size_t start, const size_t length) :
-    _row(row),
-    _start(start),
-    _length(length),
-    _pos(start),
-    _view(s_GenerateView(row, start))
-{
-}
-
-RowCellIterator::operator bool() const noexcept
-{
-    // In lieu of using start and end, this custom iterator type simply becomes bool false
-    // when we run out of items to iterate over.
-    return _pos < (_start + _length);
-}
-
-bool RowCellIterator::operator==(const RowCellIterator& it) const noexcept
-{
-    return _row == it._row &&
-           _start == it._start &&
-           _length == it._length &&
-           _pos == it._pos;
-}
-bool RowCellIterator::operator!=(const RowCellIterator& it) const noexcept
-{
-    return !(*this == it);
-}
-
-RowCellIterator& RowCellIterator::operator+=(const ptrdiff_t& movement) noexcept
-{
-    _pos += movement;
-
-    return (*this);
-}
-
-RowCellIterator& RowCellIterator::operator++() noexcept
-{
-    return this->operator+=(1);
-}
-
-RowCellIterator RowCellIterator::operator++(int) noexcept
-{
-    auto temp(*this);
-    operator++();
-    return temp;
-}
-
-RowCellIterator RowCellIterator::operator+(const ptrdiff_t& movement) noexcept
-{
-    auto temp(*this);
-    temp += movement;
-    return temp;
-}
-
-const OutputCellView& RowCellIterator::operator*() const noexcept
-{
-    return _view;
-}
-
-const OutputCellView* RowCellIterator::operator->() const noexcept
-{
-    return &_view;
-}
-
-// Routine Description:
-// - Member function to update the view to the current position in the buffer with
-//   the data held on this object.
-// Arguments:
-// - <none>
-// Return Value:
-// - <none>
-void RowCellIterator::_RefreshView()
-{
-    _view = s_GenerateView(_row, _pos);
-}
-
-// Routine Description:
-// - Static function to create a view.
-// - It's pulled out statically so it can be used during construction with just the given
-//   variables (so OutputCellView doesn't need an empty default constructor)
-// - This will infer the width of the glyph and apply the appropriate attributes to the view.
-// Arguments:
-// - view - View representing characters corresponding to a single glyph
-// - attr - Color attributes to apply to the text
-// Return Value:
-// - Object representing the view into this cell
-OutputCellView RowCellIterator::s_GenerateView(const ROW& row,
-                                               const size_t pos)
-{
-    const auto& charRow = row.GetCharRow();
-
-    const auto glyph = charRow.GlyphAt(pos);
-    const auto dbcsAttr = charRow.DbcsAttrAt(pos);
-
-    const auto textAttr = row.GetAttrRow().GetAttrByColumn(pos);
-    const auto behavior = TextAttributeBehavior::Stored;
-
-    return OutputCellView(glyph, dbcsAttr, textAttr, behavior);
-}

src/buffer/out/RowCellIterator.hpp

@@ -1,59 +0,0 @@
-/*++
-Copyright (c) Microsoft Corporation
-Licensed under the MIT license.
-
-Module Name:
-- RowCellIterator.hpp
-
-Abstract:
-- Read-only view into cells already in the input buffer.
-- This is done for performance reasons (avoid heap allocs and copies).
-
-Author:
-- Michael Niksa (MiNiksa) 12-Oct-2018
-
---*/
-
-#pragma once
-
-#include "OutputCellView.hpp"
-class ROW;
-
-class RowCellIterator final
-{
-public:
-    using iterator_category = std::forward_iterator_tag;
-    using value_type = OutputCellView;
-    using difference_type = ptrdiff_t;
-    using pointer = OutputCellView*;
-    using reference = OutputCellView&;
-
-    RowCellIterator(const ROW& row, const size_t start, const size_t length);
-    ~RowCellIterator() = default;
-
-    RowCellIterator& operator=(const RowCellIterator& it) = delete;
-
-    operator bool() const noexcept;
-
-    bool operator==(const RowCellIterator& it) const noexcept;
-    bool operator!=(const RowCellIterator& it) const noexcept;
-
-    RowCellIterator& operator+=(const ptrdiff_t& movement) noexcept;
-    RowCellIterator& operator++() noexcept;
-    RowCellIterator operator++(int) noexcept;
-    RowCellIterator operator+(const ptrdiff_t& movement) noexcept;
-
-    const OutputCellView& operator*() const noexcept;
-    const OutputCellView* operator->() const noexcept;
-
-private:
-    const ROW& _row;
-    const size_t _start;
-    const size_t _length;
-
-    size_t _pos;
-    OutputCellView _view;
-
-    void _RefreshView();
-    static OutputCellView s_GenerateView(const ROW& row, const size_t pos);
-};

src/buffer/out/TextAttributeRun.cpp

@@ -1,47 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT license.
-
-#include "precomp.h"
-#include "TextAttributeRun.hpp"
-
-TextAttributeRun::TextAttributeRun() noexcept :
-    _cchLength(0)
-{
-    SetAttributes(TextAttribute(0));
-}
-
-TextAttributeRun::TextAttributeRun(const size_t cchLength, const TextAttribute attr) noexcept :
-    _cchLength(cchLength)
-{
-    SetAttributes(attr);
-}
-
-size_t TextAttributeRun::GetLength() const noexcept
-{
-    return _cchLength;
-}
-
-void TextAttributeRun::SetLength(const size_t cchLength) noexcept
-{
-    _cchLength = cchLength;
-}
-
-void TextAttributeRun::IncrementLength() noexcept
-{
-    _cchLength++;
-}
-
-void TextAttributeRun::DecrementLength() noexcept
-{
-    _cchLength--;
-}
-
-const TextAttribute& TextAttributeRun::GetAttributes() const noexcept
-{
-    return _attributes;
-}
-
-void TextAttributeRun::SetAttributes(const TextAttribute textAttribute) noexcept
-{
-    _attributes = textAttribute;
-}

src/buffer/out/TextAttributeRun.hpp

@@ -22,25 +22,23 @@ Revision History:
 
 #include "TextAttribute.hpp"
 
-class TextAttributeRun final
+class TextAttributeRun final : public std::pair<TextAttribute, unsigned int>
 {
 public:
-    TextAttributeRun() noexcept;
-    TextAttributeRun(const size_t cchLength, const TextAttribute attr) noexcept;
+    using mybase = std::pair<TextAttribute, unsigned int>;
 
-    size_t GetLength() const noexcept;
-    void SetLength(const size_t cchLength) noexcept;
-    void IncrementLength() noexcept;
-    void DecrementLength() noexcept;
+    using mybase::mybase;
 
-    const TextAttribute& GetAttributes() const noexcept;
-    void SetAttributes(const TextAttribute textAttribute) noexcept;
+    TextAttributeRun(const size_t cchLength, const TextAttribute attr) :
+        mybase(attr, gsl::narrow<unsigned int>(cchLength))
+    {
+    }
 
-private:
-    size_t _cchLength;
-    TextAttribute _attributes;
+    size_t GetLength() const noexcept { return mybase::second; }
+    void SetLength(const size_t cchLength) noexcept { mybase::second = gsl::narrow<unsigned int>(cchLength); }
+    void IncrementLength() noexcept { mybase::second++; }
+    void DecrementLength() noexcept { mybase::second--; }
 
-#ifdef UNIT_TESTING
-    friend class AttrRowTests;
-#endif
+    const TextAttribute& GetAttributes() const noexcept { return mybase::first; }
+    void SetAttributes(const TextAttribute textAttribute) noexcept { mybase::first = textAttribute; }
 };

src/buffer/out/lib/bufferout.vcxproj

@@ -6,23 +6,20 @@
     <RootNamespace>bufferout</RootNamespace>
     <ProjectName>BufferOut</ProjectName>
     <TargetName>ConBufferOut</TargetName>
-    <ConfigurationType>StaticLibrary</ConfigurationType>
+    <ConfigurationType>StaticLibrary</ConfigurationType>
   </PropertyGroup>
   <Import Project="$(SolutionDir)src\common.build.pre.props" />
   <ItemGroup>
     <ClCompile Include="..\AttrRow.cpp" />
-    <ClCompile Include="..\AttrRowIterator.cpp" />
     <ClCompile Include="..\cursor.cpp" />
     <ClCompile Include="..\OutputCell.cpp" />
     <ClCompile Include="..\OutputCellIterator.cpp" />
     <ClCompile Include="..\OutputCellRect.cpp" />
     <ClCompile Include="..\OutputCellView.cpp" />
     <ClCompile Include="..\Row.cpp" />
-    <ClCompile Include="..\RowCellIterator.cpp" />
     <ClCompile Include="..\search.cpp" />
     <ClCompile Include="..\TextColor.cpp" />
     <ClCompile Include="..\TextAttribute.cpp" />
-    <ClCompile Include="..\TextAttributeRun.cpp" />
     <ClCompile Include="..\textBuffer.cpp" />
     <ClCompile Include="..\textBufferCellIterator.cpp" />
     <ClCompile Include="..\textBufferTextIterator.cpp" />
@@ -36,16 +33,15 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\AttrRow.hpp" />
-    <ClInclude Include="..\AttrRowIterator.hpp" />
     <ClInclude Include="..\cursor.h" />
     <ClInclude Include="..\DbcsAttribute.hpp" />
     <ClInclude Include="..\ICharRow.hpp" />
+    <ClInclude Include="..\LineRendition.hpp" />
     <ClInclude Include="..\OutputCell.hpp" />
     <ClInclude Include="..\OutputCellIterator.hpp" />
     <ClInclude Include="..\OutputCellRect.hpp" />
     <ClInclude Include="..\OutputCellView.hpp" />
     <ClInclude Include="..\Row.hpp" />
-    <ClInclude Include="..\RowCellIterator.hpp" />
     <ClInclude Include="..\search.h" />
     <ClInclude Include="..\TextColor.h" />
     <ClInclude Include="..\TextAttribute.h" />

src/buffer/out/search.cpp

@@ -97,7 +97,12 @@ bool Search::FindNext()
 // - Takes the found word and selects it in the screen buffer
 void Search::Select() const
 {
-    _uiaData.SelectNewRegion(_coordSelStart, _coordSelEnd);
+    // Convert buffer selection offsets into the equivalent screen coordinates
+    // required by SelectNewRegion, taking line renditions into account.
+    const auto& textBuffer = _uiaData.GetTextBuffer();
+    const auto selStart = textBuffer.BufferToScreenPosition(_coordSelStart);
+    const auto selEnd = textBuffer.BufferToScreenPosition(_coordSelEnd);
+    _uiaData.SelectNewRegion(selStart, selEnd);
 }
 
 // Routine Description:
@@ -141,7 +146,10 @@ COORD Search::s_GetInitialAnchor(IUiaData& uiaData, const Direction direction)
     const COORD textBufferEndPosition = uiaData.GetTextBufferEndPosition();
     if (uiaData.IsSelectionActive())
     {
-        auto anchor = uiaData.GetSelectionAnchor();
+        // Convert the screen position of the selection anchor into an equivalent
+        // buffer position to start searching, taking line rendition into account.
+        auto anchor = textBuffer.ScreenToBufferPosition(uiaData.GetSelectionAnchor());
+
         if (direction == Direction::Forward)
         {
             textBuffer.GetSize().IncrementInBoundsCircular(anchor);

src/buffer/out/sources.inc

@@ -30,17 +30,14 @@ PRECOMPILED_INCLUDE     = ..\precomp.h
 
 SOURCES= \
     ..\AttrRow.cpp \
-    ..\AttrRowIterator.cpp \
     ..\cursor.cpp    \
     ..\OutputCell.cpp \
     ..\OutputCellIterator.cpp \
     ..\OutputCellRect.cpp \
     ..\OutputCellView.cpp \
     ..\Row.cpp \
-    ..\RowCellIterator.cpp \
     ..\TextColor.cpp \
     ..\TextAttribute.cpp \
-    ..\TextAttributeRun.cpp \
     ..\textBuffer.cpp \
     ..\textBufferCellIterator.cpp \
     ..\textBufferTextIterator.cpp \

src/buffer/out/textBuffer.cpp

@@ -42,6 +42,7 @@ TextBuffer::TextBuffer(const COORD screenBufferSize,
     _currentPatternId{ 0 }
 {
     // initialize ROWs
+    _storage.reserve(static_cast<size_t>(screenBufferSize.Y));
     for (size_t i = 0; i < static_cast<size_t>(screenBufferSize.Y); ++i)
     {
         _storage.emplace_back(static_cast<SHORT>(i), screenBufferSize.X, _currentAttributes, this);
@@ -253,7 +254,7 @@ bool TextBuffer::_AssertValidDoubleByteSequence(const DbcsAttribute dbcsAttribut
         // Erase previous character into an N type.
         try
         {
-            prevRow.GetCharRow().ClearCell(coordPrevPosition.X);
+            prevRow.ClearColumn(coordPrevPosition.X);
         }
         catch (...)
         {
@@ -289,14 +290,15 @@ bool TextBuffer::_PrepareForDoubleByteSequence(const DbcsAttribute dbcsAttribute
     // We only need to compensate for leading bytes
     if (dbcsAttribute.IsLeading())
     {
-        short const sBufferWidth = GetSize().Width();
+        const auto cursorPosition = GetCursor().GetPosition();
+        const auto lineWidth = GetLineWidth(cursorPosition.Y);
 
         // If we're about to lead on the last column in the row, we need to add a padding space
-        if (GetCursor().GetPosition().X == sBufferWidth - 1)
+        if (cursorPosition.X == lineWidth - 1)
         {
             // set that we're wrapping for double byte reasons
-            CharRow& charRow = GetRowByOffset(GetCursor().GetPosition().Y).GetCharRow();
-            charRow.SetDoubleBytePadded(true);
+            auto& row = GetRowByOffset(cursorPosition.Y);
+            row.SetDoubleBytePadded(true);
 
             // then move the cursor forward and onto the next row
             fSuccess = IncrementCursor();
@@ -479,7 +481,7 @@ void TextBuffer::_AdjustWrapOnCurrentRow(const bool fSet)
     const UINT uiCurrentRowOffset = GetCursor().GetPosition().Y;
 
     // Set the wrap status as appropriate
-    GetRowByOffset(uiCurrentRowOffset).GetCharRow().SetWrapForced(fSet);
+    GetRowByOffset(uiCurrentRowOffset).SetWrapForced(fSet);
 }
 
 //Routine Description:
@@ -495,7 +497,7 @@ bool TextBuffer::IncrementCursor()
     // Cursor position is stored as logical array indices (starts at 0) for the window
     // Buffer Size is specified as the "length" of the array. It would say 80 for valid values of 0-79.
     // So subtract 1 from buffer size in each direction to find the index of the final column in the buffer
-    const short iFinalColumnIndex = GetSize().RightInclusive();
+    const short iFinalColumnIndex = GetLineWidth(GetCursor().GetPosition().Y) - 1;
 
     // Move the cursor one position to the right
     GetCursor().IncrementXPosition(1);
@@ -634,7 +636,7 @@ COORD TextBuffer::GetLastNonSpaceCharacter(std::optional<const Microsoft::Consol
 // Return Value:
 // - Coordinate position in screen coordinates of the character just before the cursor.
 // - NOTE: Will return 0,0 if already in the top left corner
-COORD TextBuffer::_GetPreviousFromCursor() const noexcept
+COORD TextBuffer::_GetPreviousFromCursor() const
 {
     COORD coordPosition = GetCursor().GetPosition();
 
@@ -648,11 +650,11 @@ COORD TextBuffer::_GetPreviousFromCursor() const noexcept
         // Otherwise, only if we're not on the top row (e.g. we don't move anywhere in the top left corner. there is no previous)
         if (coordPosition.Y > 0)
         {
-            // move the cursor to the right edge
-            coordPosition.X = GetSize().RightInclusive();
-
-            // and up one line
+            // move the cursor up one line
             coordPosition.Y--;
+
+            // and to the right edge
+            coordPosition.X = GetLineWidth(coordPosition.Y) - 1;
         }
     }
 
@@ -800,6 +802,78 @@ void TextBuffer::SetCurrentAttributes(const TextAttribute& currentAttributes) no
     _currentAttributes = currentAttributes;
 }
 
+void TextBuffer::SetCurrentLineRendition(const LineRendition lineRendition)
+{
+    const auto cursorPosition = GetCursor().GetPosition();
+    const auto rowIndex = cursorPosition.Y;
+    auto& row = GetRowByOffset(rowIndex);
+    if (row.GetLineRendition() != lineRendition)
+    {
+        row.SetLineRendition(lineRendition);
+        // If the line rendition has changed, the row can no longer be wrapped.
+        row.SetWrapForced(false);
+        // And if it's no longer single width, the right half of the row should be erased.
+        if (lineRendition != LineRendition::SingleWidth)
+        {
+            const auto fillChar = L' ';
+            auto fillAttrs = GetCurrentAttributes();
+            fillAttrs.SetStandardErase();
+            const size_t fillOffset = GetLineWidth(rowIndex);
+            const size_t fillLength = GetSize().Width() - fillOffset;
+            const auto fillData = OutputCellIterator{ fillChar, fillAttrs, fillLength };
+            row.WriteCells(fillData, fillOffset, false);
+            // We also need to make sure the cursor is clamped within the new width.
+            GetCursor().SetPosition(ClampPositionWithinLine(cursorPosition));
+        }
+        _NotifyPaint(Viewport::FromDimensions({ 0, rowIndex }, { GetSize().Width(), 1 }));
+    }
+}
+
+void TextBuffer::ResetLineRenditionRange(const size_t startRow, const size_t endRow)
+{
+    for (auto row = startRow; row < endRow; row++)
+    {
+        GetRowByOffset(row).SetLineRendition(LineRendition::SingleWidth);
+    }
+}
+
+LineRendition TextBuffer::GetLineRendition(const size_t row) const
+{
+    return GetRowByOffset(row).GetLineRendition();
+}
+
+bool TextBuffer::IsDoubleWidthLine(const size_t row) const
+{
+    return GetLineRendition(row) != LineRendition::SingleWidth;
+}
+
+SHORT TextBuffer::GetLineWidth(const size_t row) const
+{
+    // Use shift right to quickly divide the width by 2 for double width lines.
+    const auto scale = IsDoubleWidthLine(row) ? 1 : 0;
+    return GetSize().Width() >> scale;
+}
+
+COORD TextBuffer::ClampPositionWithinLine(const COORD position) const
+{
+    const SHORT rightmostColumn = GetLineWidth(position.Y) - 1;
+    return { std::min(position.X, rightmostColumn), position.Y };
+}
+
+COORD TextBuffer::ScreenToBufferPosition(const COORD position) const
+{
+    // Use shift right to quickly divide the X pos by 2 for double width lines.
+    const auto scale = IsDoubleWidthLine(position.Y) ? 1 : 0;
+    return { position.X >> scale, position.Y };
+}
+
+COORD TextBuffer::BufferToScreenPosition(const COORD position) const
+{
+    // Use shift left to quickly multiply the X pos by 2 for double width lines.
+    const auto scale = IsDoubleWidthLine(position.Y) ? 1 : 0;
+    return { position.X << scale, position.Y };
+}
+
 // Routine Description:
 // - Resets the text contents of this buffer with the default character
 //   and the default current color attributes
@@ -809,8 +883,7 @@ void TextBuffer::Reset()
 
     for (auto& row : _storage)
     {
-        row.GetCharRow().Reset();
-        row.GetAttrRow().Reset(attr);
+        row.Reset(attr);
     }
 }
 
@@ -837,11 +910,10 @@ void TextBuffer::Reset()
         const SHORT TopRowIndex = (GetFirstRowIndex() + TopRow) % currentSize.Y;
 
         // rotate rows until the top row is at index 0
-        const ROW& newTopRow = _storage.at(TopRowIndex);
-        while (&newTopRow != &_storage.front())
+        for (int i = 0; i < TopRowIndex; i++)
         {
-            _storage.push_back(std::move(_storage.front()));
-            _storage.pop_front();
+            _storage.emplace_back(std::move(_storage.front()));
+            _storage.erase(_storage.begin());
         }
 
         _SetFirstRowIndex(0);
@@ -1230,9 +1302,15 @@ void TextBuffer::_PruneHyperlinks()
     // If the buffer does not contain the same reference, we can remove that hyperlink from our map
     // This way, obsolete hyperlink references are cleared from our hyperlink map instead of hanging around
     // Get all the hyperlink references in the row we're erasing
-    auto firstRowRefs = _storage.at(_firstRow).GetAttrRow().GetHyperlinks();
-    if (!firstRowRefs.empty())
+    const auto hyperlinks = _storage.at(_firstRow).GetAttrRow().GetHyperlinks();
+
+    if (!hyperlinks.empty())
     {
+        // Move to unordered set so we can use hashed lookup of IDs instead of linear search.
+        // Only make it an unordered set now because set always heap allocates but vector
+        // doesn't when the set is empty (saving an allocation in the common case of no links.)
+        std::unordered_set<uint16_t> firstRowRefs{ hyperlinks.cbegin(), hyperlinks.cend() };
+
         const auto total = TotalRowCount();
         // Loop through all the rows in the buffer except the first row -
         // we have found all hyperlink references in the first row and put them in refs,
@@ -1254,12 +1332,12 @@ void TextBuffer::_PruneHyperlinks()
                 break;
             }
         }
-    }
 
-    // Now delete obsolete references from our map
-    for (auto hyperlinkReference : firstRowRefs)
-    {
-        RemoveHyperlinkFromMap(hyperlinkReference);
+        // Now delete obsolete references from our map
+        for (auto hyperlinkReference : firstRowRefs)
+        {
+            RemoveHyperlinkFromMap(hyperlinkReference);
+        }
     }
 }
 
@@ -1420,9 +1498,11 @@ bool TextBuffer::MoveToPreviousGlyph(til::point& pos) const
 // - blockSelection: when enabled, only get the rectangular text region,
 //                   as opposed to the text extending to the left/right
 //                   buffer margins
+// - bufferCoordinates: when enabled, treat the coordinates as relative to
+//                      the buffer rather than the screen.
 // Return Value:
 // - the delimiter class for the given char
-const std::vector<SMALL_RECT> TextBuffer::GetTextRects(COORD start, COORD end, bool blockSelection) const
+const std::vector<SMALL_RECT> TextBuffer::GetTextRects(COORD start, COORD end, bool blockSelection, bool bufferCoordinates) const
 {
     std::vector<SMALL_RECT> textRects;
 
@@ -1456,6 +1536,13 @@ const std::vector<SMALL_RECT> TextBuffer::GetTextRects(COORD start, COORD end, b
             textRow.Right = (row == lowerCoord.Y) ? lowerCoord.X : bufferSize.RightInclusive();
         }
 
+        // If we were passed screen coordinates, convert the given range into
+        // equivalent buffer offsets, taking line rendition into account.
+        if (!bufferCoordinates)
+        {
+            textRow = ScreenToBufferLine(textRow, GetLineRendition(row));
+        }
+
         _ExpandTextRow(textRow);
         textRects.emplace_back(textRow);
     }
@@ -1582,7 +1669,7 @@ const TextBuffer::TextAndColor TextBuffer::GetText(const bool includeCRLF,
         }
 
         // We apply formatting to rows if the row was NOT wrapped or formatting of wrapped rows is allowed
-        const bool shouldFormatRow = formatWrappedRows || !GetRowByOffset(iRow).GetCharRow().WasWrapForced();
+        const bool shouldFormatRow = formatWrappedRows || !GetRowByOffset(iRow).WasWrapForced();
 
         if (trimTrailingWhitespace)
         {
@@ -2039,7 +2126,6 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
     const COORD cOldLastChar = oldBuffer.GetLastNonSpaceCharacter(lastCharacterViewport);
 
     const short cOldRowsTotal = cOldLastChar.Y + 1;
-    const short cOldColsTotal = oldBuffer.GetSize().Width();
 
     COORD cNewCursorPos = { 0 };
     bool fFoundCursorPos = false;
@@ -2051,9 +2137,19 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
     {
         // Fetch the row and its "right" which is the last printable character.
         const ROW& row = oldBuffer.GetRowByOffset(iOldRow);
+        const short cOldColsTotal = oldBuffer.GetLineWidth(iOldRow);
         const CharRow& charRow = row.GetCharRow();
         short iRight = gsl::narrow_cast<short>(charRow.MeasureRight());
 
+        // If we're starting a new row, try and preserve the line rendition
+        // from the row in the original buffer.
+        const auto newBufferPos = newBuffer.GetCursor().GetPosition();
+        if (newBufferPos.X == 0)
+        {
+            auto& newRow = newBuffer.GetRowByOffset(newBufferPos.Y);
+            newRow.SetLineRendition(row.GetLineRendition());
+        }
+
         // There is a special case here. If the row has a "wrap"
         // flag on it, but the right isn't equal to the width (one
         // index past the final valid index in the row) then there
@@ -2063,7 +2159,7 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
         // included.)
         // As such, adjust the "right" to be the width of the row
         // to capture all these spaces
-        if (charRow.WasWrapForced())
+        if (row.WasWrapForced())
         {
             iRight = cOldColsTotal;
 
@@ -2072,7 +2168,7 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
             // piece of padding because of a double byte LEADING
             // character, then remove one from the "right" to
             // leave this padding out of the copy process.
-            if (charRow.WasDoubleBytePadded())
+            if (row.WasDoubleBytePadded())
             {
                 iRight--;
             }
@@ -2136,7 +2232,7 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
             // Only do so if we were not forced to wrap. If we did
             // force a word wrap, then the existing line break was
             // only because we ran out of space.
-            if (iRight < cOldColsTotal && !charRow.WasWrapForced())
+            if (iRight < cOldColsTotal && !row.WasWrapForced())
             {
                 if (iRight == cOldCursorPos.X && iOldRow == cOldCursorPos.Y)
                 {
@@ -2180,7 +2276,7 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
                     const COORD coordNewCursor = newCursor.GetPosition();
                     if (coordNewCursor.X == 0 && coordNewCursor.Y > 0)
                     {
-                        if (newBuffer.GetRowByOffset(gsl::narrow_cast<size_t>(coordNewCursor.Y) - 1).GetCharRow().WasWrapForced())
+                        if (newBuffer.GetRowByOffset(gsl::narrow_cast<size_t>(coordNewCursor.Y) - 1).WasWrapForced())
                         {
                             hr = newBuffer.NewlineCursor() ? hr : E_OUTOFMEMORY;
                         }
@@ -2213,7 +2309,7 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
 
             // If the last row of the new buffer wrapped, there's going to be one less newline needed,
             //   because the cursor is already on the next line
-            if (newBuffer.GetRowByOffset(cNewLastChar.Y).GetCharRow().WasWrapForced())
+            if (newBuffer.GetRowByOffset(cNewLastChar.Y).WasWrapForced())
             {
                 iNewlines = std::max(iNewlines - 1, 0);
             }
@@ -2221,7 +2317,7 @@ HRESULT TextBuffer::Reflow(TextBuffer& oldBuffer,
             {
                 // if this buffer didn't wrap, but the old one DID, then the d(columns) of the
                 //   old buffer will be one more than in this buffer, so new need one LESS.
-                if (oldBuffer.GetRowByOffset(cOldLastChar.Y).GetCharRow().WasWrapForced())
+                if (oldBuffer.GetRowByOffset(cOldLastChar.Y).WasWrapForced())
                 {
                     iNewlines = std::max(iNewlines - 1, 0);
                 }
@@ -2410,8 +2506,8 @@ PointTree TextBuffer::GetPatterns(const size_t firstRow, const size_t lastRow) c
     // all the text into one string and find the patterns in that string
     for (auto i = firstRow; i <= lastRow; ++i)
     {
-        auto row = GetRowByOffset(i);
-        concatAll += row.GetCharRow().GetText();
+        auto& row = GetRowByOffset(i);
+        concatAll += row.GetText();
     }
 
     // for each pattern we know of, iterate through the string

src/buffer/out/textBuffer.hpp

@@ -49,6 +49,8 @@ filling in the last row, and updating the screen.
 
 #pragma once
 
+#include <vector>
+
 #include "cursor.h"
 #include "Row.hpp"
 #include "TextAttribute.hpp"
@@ -120,6 +122,16 @@ public:
 
     void SetCurrentAttributes(const TextAttribute& currentAttributes) noexcept;
 
+    void SetCurrentLineRendition(const LineRendition lineRendition);
+    void ResetLineRenditionRange(const size_t startRow, const size_t endRow);
+    LineRendition GetLineRendition(const size_t row) const;
+    bool IsDoubleWidthLine(const size_t row) const;
+
+    SHORT GetLineWidth(const size_t row) const;
+    COORD ClampPositionWithinLine(const COORD position) const;
+    COORD ScreenToBufferPosition(const COORD position) const;
+    COORD BufferToScreenPosition(const COORD position) const;
+
     void Reset();
 
     [[nodiscard]] HRESULT ResizeTraditional(const COORD newSize) noexcept;
@@ -139,7 +151,7 @@ public:
     bool MoveToNextGlyph(til::point& pos, bool allowBottomExclusive = false) const;
     bool MoveToPreviousGlyph(til::point& pos) const;
 
-    const std::vector<SMALL_RECT> GetTextRects(COORD start, COORD end, bool blockSelection = false) const;
+    const std::vector<SMALL_RECT> GetTextRects(COORD start, COORD end, bool blockSelection, bool bufferCoordinates) const;
 
     void AddHyperlinkToMap(std::wstring_view uri, uint16_t id);
     std::wstring GetHyperlinkUriFromId(uint16_t id) const;
@@ -190,7 +202,7 @@ public:
 private:
     void _UpdateSize();
     Microsoft::Console::Types::Viewport _size;
-    std::deque<ROW> _storage;
+    std::vector<ROW> _storage;
     Cursor _cursor;
 
     SHORT _firstRow; // indexes top row (not necessarily 0)
@@ -210,7 +222,7 @@ private:
 
     void _SetFirstRowIndex(const SHORT FirstRowIndex) noexcept;
 
-    COORD _GetPreviousFromCursor() const noexcept;
+    COORD _GetPreviousFromCursor() const;
 
     void _SetWrapOnCurrentRow();
     void _AdjustWrapOnCurrentRow(const bool fSet);

src/buffer/out/textBufferCellIterator.hpp

@@ -15,8 +15,8 @@ Author(s):
 
 #pragma once
 
-#include "AttrRowIterator.hpp"
 #include "CharRow.hpp"
+#include "AttrRow.hpp"
 #include "OutputCellView.hpp"
 #include "../../types/inc/viewport.hpp"
 
@@ -55,7 +55,7 @@ protected:
     OutputCellView _view;
 
     const ROW* _pRow;
-    AttrRowIterator _attrIter;
+    ATTR_ROW::const_iterator _attrIter;
     const TextBuffer& _buffer;
     const Microsoft::Console::Types::Viewport _bounds;
     bool _exceeded;

src/buffer/out/ut_textbuffer/ReflowTests.cpp

@@ -0,0 +1,856 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "precomp.h"
+#include "WexTestClass.h"
+#include "../../inc/consoletaeftemplates.hpp"
+
+#include "../textBuffer.hpp"
+#include "../../renderer/inc/DummyRenderTarget.hpp"
+#include "../../types/inc/Utf16Parser.hpp"
+#include "../../types/inc/GlyphWidth.hpp"
+
+#include <IDataSource.h>
+
+template<>
+class WEX::TestExecution::VerifyOutputTraits<wchar_t>
+{
+public:
+    static WEX::Common::NoThrowString ToString(const wchar_t& wch)
+    {
+        return WEX::Common::NoThrowString().Format(L"'%c'", wch);
+    }
+};
+
+using namespace WEX::Common;
+using namespace WEX::Logging;
+using namespace WEX::TestExecution;
+
+namespace
+{
+    struct TestRow
+    {
+        std::wstring_view text;
+        bool wrap;
+    };
+
+    struct TestBuffer
+    {
+        COORD size;
+        std::vector<TestRow> rows;
+        COORD cursor;
+    };
+
+    struct TestCase
+    {
+        std::wstring_view name;
+        std::vector<TestBuffer> buffers;
+    };
+
+    static constexpr auto true_due_to_exact_wrap_bug{ true };
+
+    static const TestCase testCases[] = {
+        TestCase{
+            L"No reflow required",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"AB    ", false },
+                        { L"$     ", false },
+                        { L"CD    ", false },
+                        { L"EFG   ", false },
+                        { L"      ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"AB   ", false },
+                        { L"$    ", false },
+                        { L"CD   ", false },
+                        { L"EFG  ", false },
+                        { L"     ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 4, 5 },
+                    {
+                        { L"AB  ", false },
+                        { L"$   ", false },
+                        { L"CD  ", false },
+                        { L"EFG ", false },
+                        { L"    ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor remains in buffer, no circling, no original wrap",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        { L"$     ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"ABCDE", true },
+                        { L"F$   ", false }, // [BUG] EXACT WRAP. $ should be alone on next line.
+                        { L"     ", false },
+                        { L"     ", false },
+                        { L"     ", false },
+                    },
+                    { 1, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 6, 5 }, // grow width back to original
+                    {
+                        { L"ABCDEF", true_due_to_exact_wrap_bug },
+                        { L"$     ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 7, 5 }, // grow width wider than original
+                    {
+                        { L"ABCDEF$", true_due_to_exact_wrap_bug }, // EXACT WRAP BUG: $ should be alone on next line
+                        { L"       ", false },
+                        { L"       ", false },
+                        { L"       ", false },
+                        { L"       ", false },
+                    },
+                    { 6, 0 } // cursor on $
+                },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor remains in buffer, no circling, with original wrap",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", true },
+                        { L"G$    ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 1, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"ABCDE", true },
+                        { L"FG$  ", false },
+                        { L"     ", false },
+                        { L"     ", false },
+                        { L"     ", false },
+                    },
+                    { 2, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 6, 5 }, // grow width back to original
+                    {
+                        { L"ABCDEF", true },
+                        { L"G$    ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 1, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 7, 5 }, // grow width wider than original
+                    {
+                        { L"ABCDEFG", true },
+                        { L"$      ", false },
+                        { L"       ", false },
+                        { L"       ", false },
+                        { L"       ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+            },
+        },
+        TestCase{
+            L"SBCS line padded with spaces (to wrap)",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"AB    ", true }, // AB    $     CD is one long wrapped line
+                        { L"$     ", true },
+                        { L"CD    ", false },
+                        { L"EFG   ", false },
+                        { L"      ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 7, 5 }, // reduce width by 1
+                    {
+                        { L"AB    $", true },
+                        { L"     CD", true_due_to_exact_wrap_bug },
+                        { L"       ", false },
+                        { L"EFG    ", false },
+                        { L"       ", false },
+                    },
+                    { 6, 0 } // cursor on $
+                },
+                TestBuffer{
+                    { 8, 5 },
+                    {
+                        { L"AB    $ ", true },
+                        { L"    CD  ", false }, // Goes to false because we hit the end of ..CD
+                        { L"EFG     ", false }, // [BUG] EFG moves up due to exact wrap bug above
+                        { L"        ", false },
+                        { L"        ", false },
+                    },
+                    { 6, 0 } // cursor on $
+                },
+            },
+        },
+        TestCase{
+            L"DBCS, cursor remains in buffer, no circling, with original wrap",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        //--0123456--
+                        { L"カタカ", true }, // KA TA KA
+                        { L"ナ$   ", false }, // NA
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 2, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        //--012345--
+                        { L"カタ ", true }, // KA TA [FORCED SPACER]
+                        { L"カナ$", true_due_to_exact_wrap_bug }, // KA NA
+                        { L"     ", false },
+                        { L"     ", false },
+                        { L"     ", false },
+                    },
+                    { 4, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 6, 5 }, // grow width back to original
+                    {
+                        //--0123456--
+                        { L"カタカ", true }, // KA TA KA
+                        { L"ナ$   ", false }, // NA
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 2, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 7, 5 }, // grow width wider than original (by one; no visible change!)
+                    {
+                        //--0123456--
+                        { L"カタカ ", true }, // KA TA KA [FORCED SPACER]
+                        { L"ナ$    ", false }, // NA
+                        { L"       ", false },
+                        { L"       ", false },
+                        { L"       ", false },
+                    },
+                    { 2, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 8, 5 }, // grow width enough to fit second DBCS
+                    {
+                        //--01234567--
+                        { L"カタカナ", true }, // KA TA KA NA
+                        { L"$       ", false },
+                        { L"        ", false },
+                        { L"        ", false },
+                        { L"        ", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor remains in buffer, with circling, no original wrap",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        { L"$     ", false },
+                        { L"GHIJKL", false },
+                        { L"MNOPQR", false },
+                        { L"STUVWX", false },
+                    },
+                    { 0, 1 } // cursor on $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"F$   ", false },
+                        { L"GHIJK", true }, // [BUG] We should see GHIJK\n L\n MNOPQ\n R\n
+                        { L"LMNOP", true }, // The wrapping here is irregular
+                        { L"QRSTU", true },
+                        { L"VWX  ", false },
+                    },
+                    { 1, 1 } // [BUG] cursor moves to 1,1 instead of sticking with the $
+                },
+                TestBuffer{
+                    { 6, 5 }, // going back to 6,5, the data lost has been destroyed
+                    {
+                        //{ L"F$    ", false }, // [BUG] this line is erroneously destroyed too!
+                        { L"GHIJKL", true },
+                        { L"MNOPQR", true },
+                        { L"STUVWX", true },
+                        { L"      ", false },
+                        { L"      ", false }, // [BUG] this line is added
+                    },
+                    { 1, 1 }, // [BUG] cursor does not follow [H], it sticks at 1,1
+                },
+                TestBuffer{
+                    { 7, 5 }, // a number of errors are carried forward from the previous buffer
+                    {
+                        { L"GHIJKLM", true },
+                        { L"NOPQRST", true },
+                        { L"UVWX   ", false }, // [BUG] This line loses wrap for some reason
+                        { L"       ", false },
+                        { L"       ", false },
+                    },
+                    { 0, 1 }, // [BUG] The cursor moves to 0, 1 now, sticking with the [N] from before
+                },
+            },
+        },
+        TestCase{
+            // The cursor is not found during character insertion.
+            // Instead, it is found off the right edge of the text. This triggers
+            // a separate cursor found codepath in the original algorithm.
+            L"SBCS, cursor off rightmost char in non-wrapped line",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        { L"$     ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 1, 1 } // cursor *after* $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"ABCDE", true },
+                        { L"F$   ", false }, // [BUG] EXACT WRAP. $ should be alone on next line.
+                        { L"     ", false },
+                        { L"     ", false },
+                        { L"     ", false },
+                    },
+                    { 2, 1 } // cursor follows space after $ to next line
+                },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor off rightmost char in wrapped line, which is then pushed off bottom",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", true },
+                        { L"GHIJKL", true },
+                        { L"MNOPQR", true },
+                        { L"STUVWX", true },
+                        { L"YZ0 $ ", false },
+                    },
+                    { 5, 4 } // cursor *after* $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"FGHIJ", true },
+                        { L"KLMNO", true },
+                        { L"PQRST", true },
+                        { L"UVWXY", true },
+                        { L"Z0 $ ", false },
+                    },
+                    { 4, 4 } // cursor follows space after $ to newly introduced bottom line
+                },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor off in space to far right of text (end of buffer content)",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        //       v cursor
+                        { L"$     ", false },
+                        //       ^ cursor
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 5, 1 } // cursor in space far after $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"ABCDE", true },
+                        { L"F$   ", true }, // [BUG] This line is marked wrapped, and I do not know why
+                        //   v cursor
+                        { L"     ", false },
+                        //   ^ cursor
+                        { L"     ", false },
+                        { L"     ", false },
+                    },
+                    { 1, 2 } // cursor stays same linear distance from $
+                },
+                TestBuffer{
+                    { 6, 5 }, // grow back to original size
+                    {
+                        { L"ABCDEF", true_due_to_exact_wrap_bug },
+                        //      v cursor [BUG] cursor does not retain linear distance from $
+                        { L"$     ", false },
+                        //      ^ cursor
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 4, 1 } // cursor stays same linear distance from $
+                },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor off in space to far right of text (middle of buffer content)",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        //       v cursor
+                        { L"$     ", false },
+                        //       ^ cursor
+                        { L"BLAH  ", false },
+                        { L"BLAH  ", false },
+                        { L"      ", false },
+                    },
+                    { 5, 1 } // cursor in space far after $
+                },
+                TestBuffer{
+                    { 5, 5 }, // reduce width by 1
+                    {
+                        { L"ABCDE", true },
+                        { L"F$   ", false },
+                        { L"BLAH ", false },
+                        { L"BLAH ", true }, // [BUG] this line wraps, no idea why
+                        //  v cursor [BUG] cursor erroneously moved to end of all content
+                        { L"     ", false },
+                        //  ^ cursor
+                    },
+                    { 0, 4 } },
+                TestBuffer{
+                    { 6, 5 }, // grow back to original size
+                    {
+                        { L"ABCDEF", true },
+                        { L"$     ", false },
+                        { L"BLAH  ", false },
+                        //       v cursor [BUG] cursor is pulled up to previous line because it was marked wrapped
+                        { L"BLAH  ", false },
+                        //       ^ cursor
+                        { L"      ", false },
+                    },
+                    { 5, 3 } },
+            },
+        },
+        TestCase{
+            // Shrinking the buffer this much forces a multi-line wrap before the cursor
+            L"SBCS, cursor off in space to far right of text (end of buffer content), aggressive shrink",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        //       v cursor
+                        { L"$     ", false },
+                        //       ^ cursor
+                        { L"      ", false },
+                        { L"      ", false },
+                        { L"      ", false },
+                    },
+                    { 5, 1 } // cursor in space far after $
+                },
+                TestBuffer{
+                    { 2, 5 }, // reduce width aggressively
+                    {
+                        { L"CD", true },
+                        { L"EF", true },
+                        { L"$ ", true },
+                        { L"  ", true },
+                        //   v cursor
+                        { L"  ", false },
+                        //   ^ cursor
+                    },
+                    { 1, 4 } },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor off in space to far right of text (end of buffer content), fully wrapped, aggressive shrink",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", true },
+                        //       v cursor
+                        { L"$     ", true },
+                        //       ^ cursor
+                        { L"      ", true },
+                        { L"      ", true },
+                        { L"      ", true },
+                    },
+                    { 5, 1 } // cursor in space far after $
+                },
+                TestBuffer{
+                    { 2, 5 }, // reduce width aggressively
+                    {
+                        { L"EF", true },
+                        { L"$ ", true },
+                        { L"  ", true },
+                        { L"  ", true },
+                        //   v cursor [BUG] cursor does not maintain linear distance from $
+                        { L"  ", false },
+                        //   ^ cursor
+                    },
+                    { 1, 4 } },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor off in space to far right of text (middle of buffer content), fully wrapped, aggressive shrink",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", true },
+                        //       v cursor
+                        { L"$     ", true },
+                        //       ^ cursor
+                        { L"      ", true },
+                        { L"      ", true },
+                        { L"     Q", true },
+                    },
+                    { 5, 1 } // cursor in space far after $
+                },
+                TestBuffer{
+                    { 2, 5 }, // reduce width aggressively
+                    {
+                        { L"  ", true },
+                        { L"  ", true },
+                        { L"  ", true },
+                        { L" Q", true },
+                        //   v cursor [BUG] cursor jumps to end of world
+                        { L"  ", false }, // POTENTIAL [BUG] a whole new blank line is added for the cursor
+                        //   ^ cursor
+                    },
+                    { 1, 4 } },
+            },
+        },
+        TestCase{
+            L"SBCS, cursor off in space to far right of text (middle of buffer content), partially wrapped, aggressive shrink",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        //       v cursor
+                        { L"$     ", false },
+                        //       ^ cursor
+                        { L"      ", false },
+                        { L"      ", true },
+                        { L"     Q", true },
+                    },
+                    { 5, 1 } // cursor in space far after $
+                },
+                TestBuffer{
+                    { 2, 5 }, // reduce width aggressively
+                    {
+                        { L"  ", true },
+                        { L"  ", true },
+                        { L"  ", true },
+                        { L" Q", true },
+                        //  v  cursor [BUG] cursor jumps to different place than fully wrapped case
+                        { L"  ", false },
+                        //  ^  cursor
+                    },
+                    { 0, 4 } },
+            },
+        },
+        TestCase{
+            // This triggers the cursor being walked forward w/ newlines to maintain
+            // distance from the last char in the buffer
+            L"SBCS, cursor at end of buffer, otherwise same as previous test",
+            {
+                TestBuffer{
+                    { 6, 5 },
+                    {
+                        { L"ABCDEF", false },
+                        { L"$     ", false },
+                        { L"     Q", true },
+                        { L"      ", true },
+                        //       v cursor
+                        { L"      ", true },
+                        //       ^ cursor
+                    },
+                    { 5, 4 } // cursor at end of buffer
+                },
+                TestBuffer{
+                    { 2, 5 }, // reduce width aggressively
+                    {
+                        { L"  ", true },
+                        { L"  ", true },
+                        { L" Q", true },
+                        { L"  ", false },
+                        //  v  cursor [BUG] cursor loses linear distance from Q; is this important?
+                        { L"  ", false },
+                        //  ^  cursor
+                    },
+                    { 0, 4 } },
+            },
+        },
+    };
+
+#pragma region TAEF hookup for the test case array above
+    struct ArrayIndexTaefAdapterRow : public Microsoft::WRL::RuntimeClass<Microsoft::WRL::RuntimeClassFlags<Microsoft::WRL::ClassicCom | Microsoft::WRL::InhibitFtmBase>, IDataRow>
+    {
+        HRESULT RuntimeClassInitialize(const size_t index)
+        {
+            _index = index;
+            return S_OK;
+        }
+
+        STDMETHODIMP GetTestData(BSTR /*pszName*/, SAFEARRAY** ppData) override
+        {
+            const auto indexString{ wil::str_printf<std::wstring>(L"%zu", _index) };
+            auto safeArray{ SafeArrayCreateVector(VT_BSTR, 0, 1) };
+            LONG index{ 0 };
+            auto indexBstr{ wil::make_bstr(indexString.c_str()) };
+            (void)SafeArrayPutElement(safeArray, &index, indexBstr.release());
+            *ppData = safeArray;
+            return S_OK;
+        }
+
+        STDMETHODIMP GetMetadataNames(SAFEARRAY** ppMetadataNames) override
+        {
+            *ppMetadataNames = nullptr;
+            return S_FALSE;
+        }
+
+        STDMETHODIMP GetMetadata(BSTR /*pszName*/, SAFEARRAY** ppData) override
+        {
+            *ppData = nullptr;
+            return S_FALSE;
+        }
+
+        STDMETHODIMP GetName(BSTR* ppszRowName) override
+        {
+            *ppszRowName = nullptr;
+            return S_FALSE;
+        }
+
+    private:
+        size_t _index;
+    };
+
+    struct ArrayIndexTaefAdapterSource : public Microsoft::WRL::RuntimeClass<Microsoft::WRL::RuntimeClassFlags<Microsoft::WRL::ClassicCom | Microsoft::WRL::InhibitFtmBase>, IDataSource>
+    {
+        STDMETHODIMP Advance(IDataRow** ppDataRow) override
+        {
+            if (_index < std::extent<decltype(testCases)>::value)
+            {
+                Microsoft::WRL::MakeAndInitialize<ArrayIndexTaefAdapterRow>(ppDataRow, _index++);
+            }
+            else
+            {
+                *ppDataRow = nullptr;
+            }
+            return S_OK;
+        }
+
+        STDMETHODIMP Reset() override
+        {
+            _index = 0;
+            return S_OK;
+        }
+
+        STDMETHODIMP GetTestDataNames(SAFEARRAY** names) override
+        {
+            auto safeArray{ SafeArrayCreateVector(VT_BSTR, 0, 1) };
+            LONG index{ 0 };
+            auto dataNameBstr{ wil::make_bstr(L"index") };
+            (void)SafeArrayPutElement(safeArray, &index, dataNameBstr.release());
+            *names = safeArray;
+            return S_OK;
+        }
+
+        STDMETHODIMP GetTestDataType(BSTR /*name*/, BSTR* type) override
+        {
+            *type = nullptr;
+            return S_OK;
+        }
+
+    private:
+        size_t _index{ 0 };
+    };
+#pragma endregion
+}
+
+extern "C" HRESULT __declspec(dllexport) __cdecl ReflowTestDataSource(IDataSource** ppDataSource, void*)
+{
+    auto source{ Microsoft::WRL::Make<ArrayIndexTaefAdapterSource>() };
+    return source.CopyTo(ppDataSource);
+}
+
+class ReflowTests
+{
+    TEST_CLASS(ReflowTests);
+
+    static DummyRenderTarget target;
+    static std::unique_ptr<TextBuffer> _textBufferFromTestBuffer(const TestBuffer& testBuffer)
+    {
+        auto buffer = std::make_unique<TextBuffer>(testBuffer.size, TextAttribute{ 0x7 }, 0, target);
+
+        size_t i{};
+        for (const auto& testRow : testBuffer.rows)
+        {
+            auto& row{ buffer->GetRowByOffset(i) };
+
+            auto& charRow{ row.GetCharRow() };
+            row.SetWrapForced(testRow.wrap);
+
+            size_t j{};
+            for (auto it{ charRow.begin() }; it != charRow.end(); ++it)
+            {
+                // Yes, we're about to manually create a buffer. It is unpleasant.
+                const auto ch{ til::at(testRow.text, j) };
+                it->Char() = ch;
+                if (IsGlyphFullWidth(ch))
+                {
+                    it->DbcsAttr().SetLeading();
+                    it++;
+                    it->Char() = ch;
+                    it->DbcsAttr().SetTrailing();
+                }
+                else
+                {
+                    it->DbcsAttr().SetSingle();
+                }
+                j++;
+            }
+            i++;
+        }
+
+        buffer->GetCursor().SetPosition(testBuffer.cursor);
+        return buffer;
+    }
+
+    static std::unique_ptr<TextBuffer> _textBufferByReflowingTextBuffer(TextBuffer& originalBuffer, const COORD newSize)
+    {
+        auto buffer = std::make_unique<TextBuffer>(newSize, TextAttribute{ 0x7 }, 0, target);
+        TextBuffer::Reflow(originalBuffer, *buffer, std::nullopt, std::nullopt);
+        return buffer;
+    }
+
+    static void _compareTextBufferAgainstTestBuffer(const TextBuffer& buffer, const TestBuffer& testBuffer)
+    {
+        VERIFY_ARE_EQUAL(testBuffer.cursor, buffer.GetCursor().GetPosition());
+        VERIFY_ARE_EQUAL(testBuffer.size, buffer.GetSize().Dimensions());
+
+        size_t i{};
+        for (const auto& testRow : testBuffer.rows)
+        {
+            NoThrowString indexString;
+            const auto& row{ buffer.GetRowByOffset(i) };
+
+            const auto& charRow{ row.GetCharRow() };
+
+            indexString.Format(L"[Row %d]", i);
+            VERIFY_ARE_EQUAL(testRow.wrap, row.WasWrapForced(), indexString);
+
+            size_t j{};
+            for (auto it{ charRow.begin() }; it != charRow.end(); ++it)
+            {
+                indexString.Format(L"[Cell %d, %d; Text line index %d]", it - charRow.begin(), i, j);
+                // Yes, we're about to manually create a buffer. It is unpleasant.
+                const auto ch{ til::at(testRow.text, j) };
+                if (IsGlyphFullWidth(ch))
+                {
+                    // Char is full width in test buffer, so
+                    // ensure that real buffer is LEAD, TRAIL (ch)
+                    VERIFY_IS_TRUE(it->DbcsAttr().IsLeading(), indexString);
+                    VERIFY_ARE_EQUAL(ch, it->Char(), indexString);
+
+                    it++;
+                    VERIFY_IS_TRUE(it->DbcsAttr().IsTrailing(), indexString);
+                }
+                else
+                {
+                    VERIFY_IS_TRUE(it->DbcsAttr().IsSingle(), indexString);
+                }
+
+                VERIFY_ARE_EQUAL(ch, it->Char(), indexString);
+                j++;
+            }
+            i++;
+        }
+    }
+
+    TEST_METHOD(TestReflowCases)
+    {
+        BEGIN_TEST_METHOD_PROPERTIES()
+            TEST_METHOD_PROPERTY(L"DataSource", L"Export:ReflowTestDataSource")
+        END_TEST_METHOD_PROPERTIES()
+
+        WEX::TestExecution::DisableVerifyExceptions disableVerifyExceptions{};
+        WEX::TestExecution::SetVerifyOutput verifyOutputScope{ WEX::TestExecution::VerifyOutputSettings::LogOnlyFailures };
+
+        unsigned int i{};
+        TestData::TryGetValue(L"index", i); // index is produced by the ArrayIndexTaefAdapterSource above
+        const auto& testCase{ testCases[i] };
+        Log::Comment(NoThrowString().Format(L"[%zu.0] Test case \"%.*s\"", i, testCase.name.size(), testCase.name.data()));
+
+        // Create initial text buffer from Buffer 0
+        auto textBuffer{ _textBufferFromTestBuffer(testCase.buffers.front()) };
+        for (size_t bufferIndex{ 1 }; bufferIndex < testCase.buffers.size(); ++bufferIndex)
+        {
+            const auto& testBuffer{ til::at(testCase.buffers, bufferIndex) };
+            Log::Comment(NoThrowString().Format(L"[%zu.%zu] Resizing to %dx%d", i, bufferIndex, testBuffer.size.X, testBuffer.size.Y));
+
+            auto newBuffer{ _textBufferByReflowingTextBuffer(*textBuffer, testBuffer.size) };
+
+            // All future operations are based on the new buffer
+            std::swap(textBuffer, newBuffer);
+
+            _compareTextBufferAgainstTestBuffer(*textBuffer, testBuffer);
+        }
+    }
+};
+
+DummyRenderTarget ReflowTests::target{};

src/buffer/out/ut_textbuffer/TextBuffer.Unit.Tests.vcxproj

@@ -6,10 +6,11 @@
     <RootNamespace>TextBufferUnitTests</RootNamespace>
     <ProjectName>TextBuffer.Unit.Tests</ProjectName>
     <TargetName>TextBuffer.Unit.Tests</TargetName>
-    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
   </PropertyGroup>
   <Import Project="$(SolutionDir)src\common.build.pre.props" />
   <ItemGroup>
+    <ClCompile Include="ReflowTests.cpp" />
     <ClCompile Include="TextColorTests.cpp" />
     <ClCompile Include="TextAttributeTests.cpp" />
     <ClCompile Include="UnicodeStorageTests.cpp" />
@@ -18,6 +19,9 @@
     </ClCompile>
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\..\..\types\lib\types.vcxproj">
+      <Project>{18d09a24-8240-42d6-8cb6-236eee820263}</Project>
+    </ProjectReference>
     <ProjectReference Include="..\lib\bufferout.vcxproj">
       <Project>{0cf235bd-2da0-407e-90ee-c467e8bbc714}</Project>
     </ProjectReference>

src/buffer/out/ut_textbuffer/sources

@@ -14,12 +14,14 @@ DLLDEF                  =
 
 SOURCES = \
     $(SOURCES) \
+    ReflowTests.cpp \
     TextColorTests.cpp \
     TextAttributeTests.cpp \
     DefaultResource.rc \
 
 TARGETLIBS = \
     $(CONSOLE_OBJ_PATH)\buffer\out\lib\$(O)\ConBufferOut.lib \
+    $(CONSOLE_OBJ_PATH)\types\lib\$(O)\ConTypes.lib \
     $(TARGETLIBS) \
 
 # -------------------------------------

src/cascadia/CascadiaPackage/CascadiaPackage.wapproj

@@ -3,8 +3,6 @@
   <Import Project="..\..\..\common.openconsole.props" Condition="'$(OpenConsoleDir)'==''" />
   <Import Project="$(OpenConsoleDir)src\wap-common.build.pre.props" />
   <PropertyGroup Label="Configuration">
-    <!-- This is necessary so the build system doesn't think we're a .NET project... -->
-    <TargetRuntime>Native</TargetRuntime>
     <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
     <TargetPlatformMinVersion>10.0.18362.0</TargetPlatformMinVersion>
     <!--
@@ -17,6 +15,10 @@
     <AppxOSMaxVersionTestedReplaceManifestVersion>false</AppxOSMaxVersionTestedReplaceManifestVersion>
     <OCExecutionAliasName Condition="'$(WindowsTerminalBranding)'==''">wtd</OCExecutionAliasName>
     <OCExecutionAliasName Condition="'$(OCExecutionAliasName)'==''">wt</OCExecutionAliasName>
+    <!-- VS 16.8 causes WAP projects to accidentally package System.Core.dll (from the CLR).
+         This has been fixed in VS 16.9 using the property below. It's safe for us to include
+         it here, even after 16.9 comes out. -->
+    <AddAdditionalExplicitAssemblyReferences>false</AddAdditionalExplicitAssemblyReferences>
   </PropertyGroup>
   <PropertyGroup>
     <ProjectGuid>CA5CAD1A-224A-4171-B13A-F16E576FDD12</ProjectGuid>

src/cascadia/CascadiaPackage/Package-Dev.appxmanifest

@@ -12,7 +12,7 @@
   xmlns:desktop5="http://schemas.microsoft.com/appx/manifest/desktop/windows10/5"
   xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities"
   xmlns:uap5="http://schemas.microsoft.com/appx/manifest/uap/windows10/5"
-  IgnorableNamespaces="uap mp rescap">
+  IgnorableNamespaces="uap mp rescap uap3">
 
   <Identity
     Name="WindowsTerminalDev"
@@ -69,27 +69,27 @@
             Enabled="false"
             DisplayName="ms-resource:AppNameDev" />
         </uap5:Extension>
+        <uap3:Extension Category="windows.appExtensionHost">
+              <uap3:AppExtensionHost>
+                <uap3:Name>com.microsoft.windows.terminal.settings</uap3:Name>
+              </uap3:AppExtensionHost>
+        </uap3:Extension>
 
         <com:Extension Category="windows.comServer">
             <com:ComServer>
                 <com:SurrogateServer DisplayName="WindowsTerminalShellExt">
-                    <com:Class Id="9f156763-7844-4dc4-b2b1-901f640f5155" Path="WindowsTerminalShellExt.dll" ThreadingModel="STA"/>
+                    <com:Class Id="52065414-e077-47ec-a3ac-1cc5455e1b54" Path="WindowsTerminalShellExt.dll" ThreadingModel="STA"/>
                 </com:SurrogateServer>
             </com:ComServer>
         </com:Extension>
         <desktop4:Extension Category="windows.fileExplorerContextMenus">
             <desktop4:FileExplorerContextMenus>
                 <desktop5:ItemType Type="Directory">
-                    <desktop5:Verb Id="Command1" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
+                    <desktop5:Verb Id="OpenTerminalDev" Clsid="52065414-e077-47ec-a3ac-1cc5455e1b54" />
                 </desktop5:ItemType>
-                <!-- Due to a bug in the OS, this doesn't actually work right -
-                we'll get a nullptr in our implementation. So this is disabled
-                temporarily. See MSFT:24623699 for more details.
-
                 <desktop5:ItemType Type="Directory\Background">
-                    <desktop5:Verb Id="Command2" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
-                </desktop5:ItemType>
-                -->
+                  <desktop5:Verb Id="OpenTerminalDev" Clsid="52065414-e077-47ec-a3ac-1cc5455e1b54" />
+                </desktop5:ItemType>                
             </desktop4:FileExplorerContextMenus>
         </desktop4:Extension>
 

src/cascadia/CascadiaPackage/Package-Pre.appxmanifest

@@ -13,7 +13,7 @@
   xmlns:desktop4="http://schemas.microsoft.com/appx/manifest/desktop/windows10/4"
   xmlns:desktop5="http://schemas.microsoft.com/appx/manifest/desktop/windows10/5"
   xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities"
-  IgnorableNamespaces="uap mp rescap">
+  IgnorableNamespaces="uap mp rescap uap3">
 
   <Identity
     Name="Microsoft.WindowsTerminalPreview"
@@ -64,6 +64,11 @@
             <desktop:ExecutionAlias Alias="wt.exe" />
           </uap3:AppExecutionAlias>
         </uap3:Extension>
+        <uap3:Extension Category="windows.appExtensionHost">
+          <uap3:AppExtensionHost>
+            <uap3:Name>com.microsoft.windows.terminal.settings</uap3:Name>
+          </uap3:AppExtensionHost>
+        </uap3:Extension>
         <uap5:Extension Category="windows.startupTask">
           <uap5:StartupTask
             TaskId="StartTerminalOnLoginTask"
@@ -73,24 +78,18 @@
         <com:Extension Category="windows.comServer">
             <com:ComServer>
                 <com:SurrogateServer DisplayName="WindowsTerminalShellExt">
-                    <com:Class Id="9f156763-7844-4dc4-b2b1-901f640f5155" Path="WindowsTerminalShellExt.dll" ThreadingModel="STA"/>
+                    <com:Class Id="02db545a-3e20-46de-83a5-1329b1e88b6b" Path="WindowsTerminalShellExt.dll" ThreadingModel="STA"/>
                 </com:SurrogateServer>
             </com:ComServer>
         </com:Extension>
         <desktop4:Extension Category="windows.fileExplorerContextMenus">
             <desktop4:FileExplorerContextMenus>
                 <desktop5:ItemType Type="Directory">
-                    <desktop5:Verb Id="Command1" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
+                    <desktop5:Verb Id="OpenTerminalPre" Clsid="02db545a-3e20-46de-83a5-1329b1e88b6b" />
                 </desktop5:ItemType>
-                <!-- Due to a bug in the OS, this doesn't actually work right -
-                we'll get a nullptr in our implementation. So this is disabled
-                temporarily. See MSFT:24623699 for more details.
-
                 <desktop5:ItemType Type="Directory\Background">
-                    <desktop5:Verb Id="Command2" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
+                  <desktop5:Verb Id="OpenTerminalPre" Clsid="02db545a-3e20-46de-83a5-1329b1e88b6b" />
                 </desktop5:ItemType>
-                -->
-
             </desktop4:FileExplorerContextMenus>
         </desktop4:Extension>
 

src/cascadia/CascadiaPackage/Package.appxmanifest

@@ -13,7 +13,7 @@
   xmlns:desktop4="http://schemas.microsoft.com/appx/manifest/desktop/windows10/4"
   xmlns:desktop5="http://schemas.microsoft.com/appx/manifest/desktop/windows10/5"
   xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities"
-  IgnorableNamespaces="uap mp rescap">
+  IgnorableNamespaces="uap mp rescap uap3">
 
   <Identity
     Name="Microsoft.WindowsTerminal"
@@ -64,6 +64,11 @@
             <desktop:ExecutionAlias Alias="wt.exe" />
           </uap3:AppExecutionAlias>
         </uap3:Extension>
+        <uap3:Extension Category="windows.appExtensionHost">
+          <uap3:AppExtensionHost>
+            <uap3:Name>com.microsoft.windows.terminal.settings</uap3:Name>
+          </uap3:AppExtensionHost>
+        </uap3:Extension>
         <uap5:Extension Category="windows.startupTask">
           <uap5:StartupTask
             TaskId="StartTerminalOnLoginTask"
@@ -81,16 +86,11 @@
         <desktop4:Extension Category="windows.fileExplorerContextMenus">
             <desktop4:FileExplorerContextMenus>
                 <desktop5:ItemType Type="Directory">
-                    <desktop5:Verb Id="Command1" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
+                    <desktop5:Verb Id="OpenTerminalHere" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
                 </desktop5:ItemType>
-                <!-- Due to a bug in the OS, this doesn't actually work right -
-                we'll get a nullptr in our implementation. So this is disabled
-                temporarily. See MSFT:24623699 for more details.
-
                 <desktop5:ItemType Type="Directory\Background">
-                    <desktop5:Verb Id="Command2" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
+                  <desktop5:Verb Id="OpenTerminalHere" Clsid="9f156763-7844-4dc4-b2b1-901f640f5155" />
                 </desktop5:ItemType>
-                -->
             </desktop4:FileExplorerContextMenus>
         </desktop4:Extension>
 

src/cascadia/CommandlineArgs/CommandlineArgs.vcxproj

@@ -1,119 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup Label="Globals">
-    <ProjectGuid>{2658e9b0-bd84-48b7-bb5e-3d18f4df07ba}</ProjectGuid>
-    <Keyword>Win32Proj</Keyword>
-    <RootNamespace>Microsoft.Terminal.CommandlineArgs</RootNamespace>
-    <ProjectName>CommandlineArgs</ProjectName>
-    <TargetName>CommandlineArgs</TargetName>
-    <WindowsTargetPlatformMinVersion>10.0.17763.0</WindowsTargetPlatformMinVersion>
-    <ConfigurationType>StaticLibrary</ConfigurationType>
-    <SubSystem>Console</SubSystem>
-    <OpenConsoleUniversalApp>true</OpenConsoleUniversalApp>
-  </PropertyGroup>
-  <Import Project="..\..\..\common.openconsole.props" Condition="'$(OpenConsoleDir)'==''" />
-  <Import Project="$(OpenConsoleDir)src\cppwinrt.build.pre.props" />
-  <ItemDefinitionGroup>
-
-    <ClCompile>
-      <!-- For CLI11: It uses dynamic_cast to cast types around, which depends
-      on being compiled with RTTI (/GR). -->
-      <RuntimeTypeInfo>true</RuntimeTypeInfo>
-    </ClCompile>
-  </ItemDefinitionGroup>
-
-  <!-- ========================= Headers ======================== -->
-  <ItemGroup>
-    <ClInclude Include="AppCommandlineArgs.h" />
-    <ClInclude Include="Commandline.h" />
-    <ClInclude Include="pch.h" />
-  </ItemGroup>
-  <!-- ========================= Cpp Files ======================== -->
-  <ItemGroup>
-    <ClCompile Include="AppCommandlineArgs.cpp" />
-    <ClCompile Include="Commandline.cpp" />
-    <ClCompile Include="pch.cpp">
-      <PrecompiledHeader>Create</PrecompiledHeader>
-    </ClCompile>
-  </ItemGroup>
-  <!-- ========================= idl Files ======================== -->
-  <ItemGroup>
-  </ItemGroup>
-  <!-- ========================= Misc Files ======================== -->
-  <ItemGroup>
-    <None Include="packages.config" />
-  </ItemGroup>
-  <!-- ========================= Project References ======================== -->
-  <ItemGroup>
-    <!--
-      the packaging project won't recurse through our dependencies, you have to
-      make sure that if you add a cppwinrt dependency to any of these projects,
-      you also update all the consumers
-    -->
-    <ProjectReference Include="$(OpenConsoleDir)src\types\lib\types.vcxproj" />
-    <ProjectReference Include="$(OpenConsoleDir)src\cascadia\WinRTUtils\WinRTUtils.vcxproj">
-      <Project>{CA5CAD1A-039A-4929-BA2A-8BEB2E4106FE}</Project>
-      <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
-    </ProjectReference>
-    <!-- For whatever reason, we can't include the TerminalControl and
-    TerminalSettings projects' winmds via project references. So we'll have to
-    manually include the winmds as References below -->
-  </ItemGroup>
-  <PropertyGroup>
-    <!-- This is a hack to get the ARM64 CI build working. See
-    https://github.com/Microsoft/msbuild/issues/3746 - it looks like MsBuild
-    just has a bug in it.-->
-    <ResolveAssemblyWarnOrErrorOnTargetArchitectureMismatch>Warning</ResolveAssemblyWarnOrErrorOnTargetArchitectureMismatch>
-  </PropertyGroup>
-  <ItemGroup>
-    <!-- Manually add references to each of our dependent winmds. Mark them as
-    private=false and CopyLocalSatelliteAssemblies=false, so that we don't
-    propagate them upwards (which can make referencing this project result in
-    duplicate type definitions)-->
-
-    <!-- Despite this lib only _really_ depending on the settings model, we need
-    to reference Connection, Control, and MUX here, because they have types that
-    TSM depends on, and the midl compiler will be mad if it can't find them. -->
-
-    <Reference Include="Microsoft.Terminal.TerminalConnection">
-      <HintPath>$(OpenConsoleCommonOutDir)TerminalConnection\Microsoft.Terminal.TerminalConnection.winmd</HintPath>
-      <IsWinMDFile>true</IsWinMDFile>
-      <Private>false</Private>
-      <CopyLocalSatelliteAssemblies>false</CopyLocalSatelliteAssemblies>
-    </Reference>
-    <Reference Include="Microsoft.Terminal.TerminalControl">
-      <HintPath>$(OpenConsoleCommonOutDir)TerminalControl\Microsoft.Terminal.TerminalControl.winmd</HintPath>
-      <IsWinMDFile>true</IsWinMDFile>
-      <Private>false</Private>
-      <CopyLocalSatelliteAssemblies>false</CopyLocalSatelliteAssemblies>
-    </Reference>
-    <Reference Include="Microsoft.Terminal.Settings.Model">
-      <HintPath>$(OpenConsoleCommonOutDir)Microsoft.Terminal.Settings.Model\Microsoft.Terminal.Settings.Model.winmd</HintPath>
-      <IsWinMDFile>true</IsWinMDFile>
-      <Private>false</Private>
-      <CopyLocalSatelliteAssemblies>false</CopyLocalSatelliteAssemblies>
-    </Reference>
-  </ItemGroup>
-  <!-- ====================== Compiler & Linker Flags ===================== -->
-  <ItemDefinitionGroup>
-    <ClCompile>
-      <PrecompiledHeaderFile>pch.h</PrecompiledHeaderFile>
-      <AdditionalIncludeDirectories>..;%(AdditionalIncludeDirectories);</AdditionalIncludeDirectories>
-      <!-- Manually disable unreachable code warning, because jconcpp has a ton of that. -->
-      <DisableSpecificWarnings>4702;%(DisableSpecificWarnings)</DisableSpecificWarnings>
-    </ClCompile>
-    <Link>
-      <AdditionalDependencies>WindowsApp.lib;shell32.lib;%(AdditionalDependencies)</AdditionalDependencies>
-    </Link>
-  </ItemDefinitionGroup>
-  <!-- ========================= Globals ======================== -->
-  <Import Project="$(OpenConsoleDir)src\cppwinrt.build.post.props" />
-  <Import Project="..\..\..\packages\Microsoft.UI.Xaml.2.5.0-prerelease.201202003\build\native\Microsoft.UI.Xaml.targets" Condition="Exists('..\..\..\packages\Microsoft.UI.Xaml.2.5.0-prerelease.201202003\build\native\Microsoft.UI.Xaml.targets')" />
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
-    <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
-    </PropertyGroup>
-    <Error Condition="!Exists('$(OpenConsoleDir)\packages\Microsoft.UI.Xaml.2.5.0-prerelease.201202003\build\native\Microsoft.UI.Xaml.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(OpenConsoleDir)\packages\Microsoft.UI.Xaml.2.5.0-prerelease.201202003\build\native\Microsoft.UI.Xaml.targets'))" />
-  </Target>
-  <!-- <Import Project="$(SolutionDir)build\rules\CollectWildcardResources.targets" /> -->
-</Project>

src/cascadia/CommandlineArgs/pch.h

@@ -1,53 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT license.
-//
-// pch.h
-// Header for platform projection include files
-//
-
-#pragma once
-
-#define WIN32_LEAN_AND_MEAN
-#define NOMCX
-#define NOHELP
-#define NOCOMM
-
-// Manually include til after we include Windows.Foundation to give it winrt superpowers
-#define BLOCK_TIL
-#include <LibraryIncludes.h>
-// This is inexplicable, but for whatever reason, cppwinrt conflicts with the
-//      SDK definition of this function, so the only fix is to undef it.
-// from WinBase.h
-// Windows::UI::Xaml::Media::Animation::IStoryboard::GetCurrentTime
-#ifdef GetCurrentTime
-#undef GetCurrentTime
-#endif
-
-#include <wil/cppwinrt.h>
-
-#include <unknwn.h>
-
-#include <hstring.h>
-
-#include <winrt/Windows.Foundation.h>
-#include <winrt/Windows.Foundation.Collections.h>
-// You might think "we're not doing any UI in this lib", and you'd be right.
-// However, we need this for Windows.UI.Color
-#include <winrt/windows.ui.h>
-
-// Including TraceLogging essentials for the binary
-#include <TraceLoggingProvider.h>
-#include <winmeta.h>
-TRACELOGGING_DECLARE_PROVIDER(g_hTerminalAppProvider);
-#include <telemetry/ProjectTelemetry.h>
-#include <TraceLoggingActivity.h>
-
-#include <shellapi.h>
-#include <shobjidl_core.h>
-
-#include <winrt/Microsoft.Terminal.Settings.Model.h>
-
-#include <CLI11/CLI11.hpp>
-
-// Manually include til after we include Windows.Foundation to give it winrt superpowers
-#include "til.h"

src/cascadia/LocalTests_SettingsModel/ColorSchemeTests.cpp

@@ -35,6 +35,7 @@ namespace SettingsModelLocalTests
         TEST_METHOD(CanLayerColorScheme);
         TEST_METHOD(LayerColorSchemeProperties);
         TEST_METHOD(LayerColorSchemesOnArray);
+        TEST_METHOD(UpdateSchemeReferences);
 
         TEST_CLASS_SETUP(ClassSetup)
         {
@@ -290,4 +291,81 @@ namespace SettingsModelLocalTests
             VERIFY_ARE_EQUAL(ARGB(0, 7, 7, 7), scheme2->_Background);
         }
     }
+
+    void ColorSchemeTests::UpdateSchemeReferences()
+    {
+        const std::string settingsString{ R"json({
+                                                "defaultProfile": "Inherited reference",
+                                                "profiles": {
+                                                    "defaults": {
+                                                        "colorScheme": "Scheme 1"
+                                                    },
+                                                    "list": [
+                                                        {
+                                                            "name": "Explicit scheme reference",
+                                                            "colorScheme": "Scheme 1"
+                                                        },
+                                                        {
+                                                            "name": "Explicit reference; hidden",
+                                                            "colorScheme": "Scheme 1",
+                                                            "hidden": true
+                                                        },
+                                                        {
+                                                            "name": "Inherited reference"
+                                                        },
+                                                        {
+                                                            "name": "Different reference",
+                                                            "colorScheme": "Scheme 2"
+                                                        }
+                                                    ]
+                                                },
+                                                "schemes": [
+                                                    { "name": "Scheme 1" },
+                                                    { "name": "Scheme 2" },
+                                                    { "name": "Scheme 1 (renamed)" }
+                                                ]
+                                            })json" };
+
+        auto settings{ winrt::make_self<CascadiaSettings>(false) };
+        settings->_ParseJsonString(settingsString, false);
+        settings->_ApplyDefaultsFromUserSettings();
+        settings->LayerJson(settings->_userSettings);
+        settings->_ValidateSettings();
+
+        // update all references to "Scheme 1"
+        const auto newName{ L"Scheme 1 (renamed)" };
+        settings->UpdateColorSchemeReferences(L"Scheme 1", newName);
+
+        // verify profile defaults
+        Log::Comment(L"Profile Defaults");
+        VERIFY_ARE_EQUAL(newName, settings->ProfileDefaults().ColorSchemeName());
+        VERIFY_IS_TRUE(settings->ProfileDefaults().HasColorSchemeName());
+
+        // verify all other profiles
+        const auto& profiles{ settings->AllProfiles() };
+        {
+            const auto& prof{ profiles.GetAt(0) };
+            Log::Comment(prof.Name().c_str());
+            VERIFY_ARE_EQUAL(newName, prof.ColorSchemeName());
+            VERIFY_IS_TRUE(prof.HasColorSchemeName());
+        }
+        {
+            const auto& prof{ profiles.GetAt(1) };
+            Log::Comment(prof.Name().c_str());
+            VERIFY_ARE_EQUAL(newName, prof.ColorSchemeName());
+            VERIFY_IS_TRUE(prof.HasColorSchemeName());
+        }
+        {
+            const auto& prof{ profiles.GetAt(2) };
+            Log::Comment(prof.Name().c_str());
+            VERIFY_ARE_EQUAL(newName, prof.ColorSchemeName());
+            VERIFY_IS_FALSE(prof.HasColorSchemeName());
+        }
+        {
+            const auto& prof{ profiles.GetAt(3) };
+            Log::Comment(prof.Name().c_str());
+            VERIFY_ARE_EQUAL(L"Scheme 2", prof.ColorSchemeName());
+            VERIFY_IS_TRUE(prof.HasColorSchemeName());
+        }
+    }
 }

src/cascadia/LocalTests_SettingsModel/CommandTests.cpp

@@ -9,7 +9,7 @@
 
 using namespace Microsoft::Console;
 using namespace winrt::Microsoft::Terminal::Settings::Model;
-using namespace winrt::Microsoft::Terminal::TerminalControl;
+using namespace winrt::Microsoft::Terminal::Control;
 using namespace winrt::Windows::Foundation::Collections;
 using namespace WEX::Logging;
 using namespace WEX::TestExecution;
@@ -37,10 +37,13 @@ namespace SettingsModelLocalTests
         TEST_METHOD(ManyCommandsSameAction);
         TEST_METHOD(LayerCommand);
         TEST_METHOD(TestSplitPaneArgs);
+        TEST_METHOD(TestSplitPaneBadSize);
         TEST_METHOD(TestResourceKeyName);
         TEST_METHOD(TestAutogeneratedName);
         TEST_METHOD(TestLayerOnAutogeneratedName);
 
+        TEST_METHOD(TestGenerateCommandline);
+
         TEST_CLASS_SETUP(ClassSetup)
         {
             InitializeJsonReader();
@@ -147,7 +150,8 @@ namespace SettingsModelLocalTests
             { "name": "command1", "command": { "action": "splitPane", "split": "vertical" } },
             { "name": "command2", "command": { "action": "splitPane", "split": "horizontal" } },
             { "name": "command4", "command": { "action": "splitPane" } },
-            { "name": "command5", "command": { "action": "splitPane", "split": "auto" } }
+            { "name": "command5", "command": { "action": "splitPane", "split": "auto" } },
+            { "name": "command6", "command": { "action": "splitPane", "size": 0.25 } },
         ])" };
 
         const auto commands0Json = VerifyParseSucceeded(commands0String);
@@ -156,7 +160,7 @@ namespace SettingsModelLocalTests
         VERIFY_ARE_EQUAL(0u, commands.Size());
         auto warnings = implementation::Command::LayerJson(commands, commands0Json);
         VERIFY_ARE_EQUAL(0u, warnings.size());
-        VERIFY_ARE_EQUAL(4u, commands.Size());
+        VERIFY_ARE_EQUAL(5u, commands.Size());
 
         {
             auto command = commands.Lookup(L"command1");
@@ -167,6 +171,7 @@ namespace SettingsModelLocalTests
             VERIFY_IS_NOT_NULL(realArgs);
             // Verify the args have the expected value
             VERIFY_ARE_EQUAL(SplitState::Vertical, realArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(0.5, realArgs.SplitSize());
         }
         {
             auto command = commands.Lookup(L"command2");
@@ -177,6 +182,7 @@ namespace SettingsModelLocalTests
             VERIFY_IS_NOT_NULL(realArgs);
             // Verify the args have the expected value
             VERIFY_ARE_EQUAL(SplitState::Horizontal, realArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(0.5, realArgs.SplitSize());
         }
         {
             auto command = commands.Lookup(L"command4");
@@ -187,6 +193,7 @@ namespace SettingsModelLocalTests
             VERIFY_IS_NOT_NULL(realArgs);
             // Verify the args have the expected value
             VERIFY_ARE_EQUAL(SplitState::Automatic, realArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(0.5, realArgs.SplitSize());
         }
         {
             auto command = commands.Lookup(L"command5");
@@ -197,8 +204,51 @@ namespace SettingsModelLocalTests
             VERIFY_IS_NOT_NULL(realArgs);
             // Verify the args have the expected value
             VERIFY_ARE_EQUAL(SplitState::Automatic, realArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(0.5, realArgs.SplitSize());
+        }
+        {
+            auto command = commands.Lookup(L"command6");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Automatic, realArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(0.25, realArgs.SplitSize());
         }
     }
+
+    void CommandTests::TestSplitPaneBadSize()
+    {
+        const std::string commands0String{ R"([
+            { "name": "command1", "command": { "action": "splitPane", "size": 0.25 } },
+            { "name": "command2", "command": { "action": "splitPane", "size": 1.0 } },
+            { "name": "command3", "command": { "action": "splitPane", "size": 0 } },
+            { "name": "command4", "command": { "action": "splitPane", "size": 50 } },
+        ])" };
+
+        const auto commands0Json = VerifyParseSucceeded(commands0String);
+
+        IMap<winrt::hstring, Command> commands = winrt::single_threaded_map<winrt::hstring, Command>();
+        VERIFY_ARE_EQUAL(0u, commands.Size());
+        auto warnings = implementation::Command::LayerJson(commands, commands0Json);
+        VERIFY_ARE_EQUAL(3u, warnings.size());
+        VERIFY_ARE_EQUAL(1u, commands.Size());
+
+        {
+            auto command = commands.Lookup(L"command1");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Automatic, realArgs.SplitStyle());
+            VERIFY_ARE_EQUAL(0.25, realArgs.SplitSize());
+        }
+    }
+
     void CommandTests::TestResourceKeyName()
     {
         // This test checks looking up a name from a resource key.
@@ -227,14 +277,6 @@ namespace SettingsModelLocalTests
 
     void CommandTests::TestAutogeneratedName()
     {
-        // Tests run in Helix can't report Skipped until GH#7286 is resolved.
-        // Set ignore flag to make Helix run completely overlook it.
-        BEGIN_TEST_METHOD_PROPERTIES()
-            TEST_METHOD_PROPERTY(L"Ignore", L"True")
-        END_TEST_METHOD_PROPERTIES()
-
-        // This test to be corrected as a part of GH#7281
-
         // This test ensures that we'll correctly create commands for actions
         // that don't have given names, pursuant to the spec in GH#6532.
 
@@ -321,4 +363,145 @@ namespace SettingsModelLocalTests
             VERIFY_ARE_EQUAL(SplitState::Vertical, realArgs.SplitStyle());
         }
     }
+
+    void CommandTests::TestGenerateCommandline()
+    {
+        const WEX::TestExecution::DisableVerifyExceptions disableExceptionsScope;
+
+        const std::string commands0String{ R"([
+            {
+                "name":"action0",
+                "command": { "action": "newWindow" }
+            },
+            {
+                "name":"action1",
+                "command": { "action": "newTab", "profile": "foo" }
+            },
+            {
+                "name":"action2",
+                "command": { "action": "newWindow", "profile": "foo" }
+            },
+            {
+                "name":"action3",
+                "command": { "action": "newWindow", "commandline": "bar.exe" }
+            },
+            {
+                "name":"action4",
+                "command": { "action": "newWindow", "commandline": "pop.exe ya ha ha" }
+            },
+            {
+                "name":"action5",
+                "command": { "action": "newWindow", "commandline": "pop.exe \"ya ha ha\"" }
+            },
+            {
+                "name":"action6",
+                "command": { "action": "newWindow", "startingDirectory":"C:\\foo", "commandline": "bar.exe" }
+            },
+        ])" };
+
+        const auto commands0Json = VerifyParseSucceeded(commands0String);
+
+        IMap<winrt::hstring, Command> commands = winrt::single_threaded_map<winrt::hstring, Command>();
+        VERIFY_ARE_EQUAL(0u, commands.Size());
+        auto warnings = implementation::Command::LayerJson(commands, commands0Json);
+        VERIFY_ARE_EQUAL(0u, warnings.size());
+        VERIFY_ARE_EQUAL(7u, commands.Size());
+
+        {
+            auto command = commands.Lookup(L"action0");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::NewWindow, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<NewWindowArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            const auto& terminalArgs = realArgs.TerminalArgs();
+            VERIFY_IS_NOT_NULL(terminalArgs);
+            auto cmdline = terminalArgs.ToCommandline();
+            VERIFY_ARE_EQUAL(L"", cmdline);
+        }
+
+        {
+            auto command = commands.Lookup(L"action1");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<NewTabArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            const auto& terminalArgs = realArgs.TerminalArgs();
+            VERIFY_IS_NOT_NULL(terminalArgs);
+            auto cmdline = terminalArgs.ToCommandline();
+            VERIFY_ARE_EQUAL(L"--profile \"foo\"", cmdline);
+        }
+
+        {
+            auto command = commands.Lookup(L"action2");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::NewWindow, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<NewWindowArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            const auto& terminalArgs = realArgs.TerminalArgs();
+            VERIFY_IS_NOT_NULL(terminalArgs);
+            auto cmdline = terminalArgs.ToCommandline();
+            VERIFY_ARE_EQUAL(L"--profile \"foo\"", cmdline);
+        }
+
+        {
+            auto command = commands.Lookup(L"action3");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::NewWindow, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<NewWindowArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            const auto& terminalArgs = realArgs.TerminalArgs();
+            VERIFY_IS_NOT_NULL(terminalArgs);
+            auto cmdline = terminalArgs.ToCommandline();
+            VERIFY_ARE_EQUAL(L"-- \"bar.exe\"", cmdline);
+        }
+
+        {
+            auto command = commands.Lookup(L"action4");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::NewWindow, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<NewWindowArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            const auto& terminalArgs = realArgs.TerminalArgs();
+            VERIFY_IS_NOT_NULL(terminalArgs);
+            auto cmdline = terminalArgs.ToCommandline();
+            Log::Comment(NoThrowString().Format(
+                L"cmdline: \"%s\"", cmdline.c_str()));
+            VERIFY_ARE_EQUAL(L"-- \"pop.exe ya ha ha\"", terminalArgs.ToCommandline());
+        }
+
+        {
+            auto command = commands.Lookup(L"action5");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::NewWindow, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<NewWindowArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            const auto& terminalArgs = realArgs.TerminalArgs();
+            VERIFY_IS_NOT_NULL(terminalArgs);
+            auto cmdline = terminalArgs.ToCommandline();
+            Log::Comment(NoThrowString().Format(
+                L"cmdline: \"%s\"", cmdline.c_str()));
+            VERIFY_ARE_EQUAL(L"-- \"pop.exe \"ya ha ha\"\"", terminalArgs.ToCommandline());
+        }
+
+        {
+            auto command = commands.Lookup(L"action6");
+            VERIFY_IS_NOT_NULL(command);
+            VERIFY_IS_NOT_NULL(command.Action());
+            VERIFY_ARE_EQUAL(ShortcutAction::NewWindow, command.Action().Action());
+            const auto& realArgs = command.Action().Args().try_as<NewWindowArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            const auto& terminalArgs = realArgs.TerminalArgs();
+            VERIFY_IS_NOT_NULL(terminalArgs);
+            auto cmdline = terminalArgs.ToCommandline();
+            Log::Comment(NoThrowString().Format(
+                L"cmdline: \"%s\"", cmdline.c_str()));
+            VERIFY_ARE_EQUAL(L"--startingDirectory \"C:\\foo\" -- \"bar.exe\"", terminalArgs.ToCommandline());
+        }
+    }
 }

src/cascadia/LocalTests_SettingsModel/DeserializationTests.cpp

@@ -15,7 +15,7 @@ using namespace WEX::Logging;
 using namespace WEX::TestExecution;
 using namespace WEX::Common;
 using namespace winrt::Microsoft::Terminal::Settings::Model;
-using namespace winrt::Microsoft::Terminal::TerminalControl;
+using namespace winrt::Microsoft::Terminal::Control;
 
 namespace SettingsModelLocalTests
 {
@@ -79,6 +79,7 @@ namespace SettingsModelLocalTests
         TEST_METHOD(TestCommandsAndKeybindings);
 
         TEST_METHOD(TestNestedCommandWithoutName);
+        TEST_METHOD(TestNestedCommandWithBadSubCommands);
         TEST_METHOD(TestUnbindNestedCommand);
         TEST_METHOD(TestRebindNestedCommand);
 
@@ -1376,7 +1377,7 @@ namespace SettingsModelLocalTests
                 },
                 {
                     "name": "parent",
-                    "commands": [                        
+                    "commands": [
                         { "command": { "action": "setColorScheme", "colorScheme": "invalidScheme" } }
                     ]
                 }
@@ -1403,11 +1404,11 @@ namespace SettingsModelLocalTests
                 },
                 {
                     "name": "grandparent",
-                    "commands": [                        
+                    "commands": [
                         {
                             "name": "parent",
                             "commands": [
-                                { 
+                                {
                                     "command": { "action": "setColorScheme", "colorScheme": "invalidScheme" }
                                 }
                             ]
@@ -1909,7 +1910,8 @@ namespace SettingsModelLocalTests
             "keybindings": [
                 { "command": { "action": "splitPane", "split":"auto" }, "keys": [ "ctrl+alt+t", "ctrl+a" ] },
                 { "command": { "action": "moveFocus" }, "keys": [ "ctrl+a" ] },
-                { "command": { "action": "resizePane" }, "keys": [ "ctrl+b" ] }
+                { "command": { "action": "resizePane" }, "keys": [ "ctrl+b" ] },
+                { "name": "invalid nested", "commands":[ { "name" : "hello" }, { "name" : "world" } ] }
             ]
         })" };
 
@@ -1918,18 +1920,20 @@ namespace SettingsModelLocalTests
 
         VERIFY_ARE_EQUAL(0u, settings->_globals->_keymap->_keyShortcuts.size());
 
-        VERIFY_ARE_EQUAL(3u, settings->_globals->_keybindingsWarnings.size());
+        VERIFY_ARE_EQUAL(4u, settings->_globals->_keybindingsWarnings.size());
         VERIFY_ARE_EQUAL(SettingsLoadWarnings::TooManyKeysForChord, settings->_globals->_keybindingsWarnings.at(0));
         VERIFY_ARE_EQUAL(SettingsLoadWarnings::MissingRequiredParameter, settings->_globals->_keybindingsWarnings.at(1));
         VERIFY_ARE_EQUAL(SettingsLoadWarnings::MissingRequiredParameter, settings->_globals->_keybindingsWarnings.at(2));
+        VERIFY_ARE_EQUAL(SettingsLoadWarnings::FailedToParseSubCommands, settings->_globals->_keybindingsWarnings.at(3));
 
         settings->_ValidateKeybindings();
 
-        VERIFY_ARE_EQUAL(4u, settings->_warnings.Size());
+        VERIFY_ARE_EQUAL(5u, settings->_warnings.Size());
         VERIFY_ARE_EQUAL(SettingsLoadWarnings::AtLeastOneKeybindingWarning, settings->_warnings.GetAt(0));
         VERIFY_ARE_EQUAL(SettingsLoadWarnings::TooManyKeysForChord, settings->_warnings.GetAt(1));
         VERIFY_ARE_EQUAL(SettingsLoadWarnings::MissingRequiredParameter, settings->_warnings.GetAt(2));
         VERIFY_ARE_EQUAL(SettingsLoadWarnings::MissingRequiredParameter, settings->_warnings.GetAt(3));
+        VERIFY_ARE_EQUAL(SettingsLoadWarnings::FailedToParseSubCommands, settings->_warnings.GetAt(4));
     }
 
     void DeserializationTests::ValidateExecuteCommandlineWarning()
@@ -2316,6 +2320,53 @@ namespace SettingsModelLocalTests
         VERIFY_ARE_EQUAL(0u, commands.Size());
     }
 
+    void DeserializationTests::TestNestedCommandWithBadSubCommands()
+    {
+        // This test tests a nested command without a name specified. This type
+        // of command should just be ignored, since we can't auto-generate names
+        // for nested commands, they _must_ have names specified.
+
+        const std::string settingsJson{ R"(
+        {
+            "defaultProfile": "{6239a42c-0000-49a3-80bd-e8fdd045185c}",
+            "profiles": [
+                {
+                    "name": "profile0",
+                    "guid": "{6239a42c-0000-49a3-80bd-e8fdd045185c}",
+                    "historySize": 1,
+                    "commandline": "cmd.exe"
+                }
+            ],
+            "actions": [
+                {
+                    "name": "nested command",
+                    "commands": [
+                        {
+                            "name": "child1"
+                        },
+                        {
+                            "name": "child2"
+                        }
+                    ]
+                },
+            ],
+            "schemes": [ { "name": "Campbell" } ] // This is included here to prevent settings validation errors.
+        })" };
+
+        VerifyParseSucceeded(settingsJson);
+
+        auto settings = winrt::make_self<implementation::CascadiaSettings>();
+        settings->_ParseJsonString(settingsJson, false);
+        settings->LayerJson(settings->_userSettings);
+        auto commands = settings->_globals->Commands();
+        settings->_ValidateSettings();
+
+        VERIFY_ARE_EQUAL(2u, settings->_warnings.Size());
+        VERIFY_ARE_EQUAL(SettingsLoadWarnings::AtLeastOneKeybindingWarning, settings->_warnings.GetAt(0));
+        VERIFY_ARE_EQUAL(SettingsLoadWarnings::FailedToParseSubCommands, settings->_warnings.GetAt(1));
+        VERIFY_ARE_EQUAL(0u, commands.Size());
+    }
+
     void DeserializationTests::TestUnbindNestedCommand()
     {
         // Test that layering a command with `"commands": null` set will unbind a command that already exists.

src/cascadia/LocalTests_SettingsModel/KeyBindingsTests.cpp

@@ -11,7 +11,7 @@
 
 using namespace Microsoft::Console;
 using namespace winrt::Microsoft::Terminal::Settings::Model;
-using namespace winrt::Microsoft::Terminal::TerminalControl;
+using namespace winrt::Microsoft::Terminal::Control;
 using namespace WEX::Logging;
 using namespace WEX::TestExecution;
 using namespace WEX::Common;

src/cascadia/LocalTests_SettingsModel/SerializationTests.cpp

@@ -15,7 +15,7 @@ using namespace WEX::Logging;
 using namespace WEX::TestExecution;
 using namespace WEX::Common;
 using namespace winrt::Microsoft::Terminal::Settings::Model;
-using namespace winrt::Microsoft::Terminal::TerminalControl;
+using namespace winrt::Microsoft::Terminal::Control;
 
 namespace SettingsModelLocalTests
 {
@@ -84,7 +84,7 @@ namespace SettingsModelLocalTests
                 "initialPosition": ",",
                 "launchMode": "default",
                 "alwaysOnTop": false,
-
+                "inputServiceWarning": true,
                 "copyOnSelect": false,
                 "copyFormatting": "all",
                 "wordDelimiters": " /\\()\"'-.,:;<>~!@#$%^&*|+=[]{}~?\u2502",
@@ -226,6 +226,7 @@ namespace SettingsModelLocalTests
         const std::string settingsString{ R"({
                                                 "$schema": "https://aka.ms/terminal-profiles-schema",
                                                 "defaultProfile": "{61c54bbd-1111-5271-96e7-009a87ff44bf}",
+                                                "disabledProfileSources": [ "Windows.Terminal.Wsl" ],
 
                                                 "profiles": {
                                                     "defaults": {

src/cascadia/LocalTests_SettingsModel/SettingsModel.LocalTests.vcxproj

@@ -40,6 +40,7 @@
     <ClCompile Include="CommandTests.cpp" />
     <ClCompile Include="DeserializationTests.cpp" />
     <ClCompile Include="SerializationTests.cpp" />
+    <ClCompile Include="TerminalSettingsTests.cpp" />
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>
     </ClCompile>
@@ -57,7 +58,7 @@
 
     <!-- If you don't reference these projects here, the
     _ConsoleGenerateAdditionalWinmdManifests step won't gather the winmd's -->
-    <ProjectReference Include="$(OpenConsoleDir)src\cascadia\TerminalControl\TerminalControl.vcxproj" />
+    <ProjectReference Include="$(OpenConsoleDir)src\cascadia\TerminalControl\dll\TerminalControl.vcxproj" />
     <ProjectReference Include="$(OpenConsoleDir)src\cascadia\TerminalConnection\TerminalConnection.vcxproj" />
     <ProjectReference Include="$(OpenConsoleDir)\src\cascadia\TerminalSettingsModel\dll\Microsoft.Terminal.Settings.Model.vcxproj" />
   </ItemGroup>

src/cascadia/LocalTests_SettingsModel/TerminalSettingsTests.cpp

@@ -0,0 +1,543 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "pch.h"
+
+#include "../TerminalSettingsModel/CascadiaSettings.h"
+#include "../TerminalSettingsModel/TerminalSettings.h"
+#include "TestUtils.h"
+
+using namespace Microsoft::Console;
+using namespace WEX::Logging;
+using namespace WEX::TestExecution;
+using namespace WEX::Common;
+using namespace winrt::Microsoft::Terminal::Settings::Model;
+using namespace winrt::Microsoft::Terminal::Control;
+
+namespace SettingsModelLocalTests
+{
+    // TODO:microsoft/terminal#3838:
+    // Unfortunately, these tests _WILL NOT_ work in our CI. We're waiting for
+    // an updated TAEF that will let us install framework packages when the test
+    // package is deployed. Until then, these tests won't deploy in CI.
+
+    class TerminalSettingsTests
+    {
+        // Use a custom AppxManifest to ensure that we can activate winrt types
+        // from our test. This property will tell taef to manually use this as
+        // the AppxManifest for this test class.
+        // This does not yet work for anything XAML-y. See TabTests.cpp for more
+        // details on that.
+        BEGIN_TEST_CLASS(TerminalSettingsTests)
+            TEST_CLASS_PROPERTY(L"RunAs", L"UAP")
+            TEST_CLASS_PROPERTY(L"UAP:AppXManifest", L"TestHostAppXManifest.xml")
+        END_TEST_CLASS()
+
+        TEST_METHOD(TryCreateWinRTType);
+
+        TEST_METHOD(TestTerminalArgsForBinding);
+
+        TEST_METHOD(MakeSettingsForProfileThatDoesntExist);
+        TEST_METHOD(MakeSettingsForDefaultProfileThatDoesntExist);
+
+        TEST_METHOD(TestLayerProfileOnColorScheme);
+
+        TEST_CLASS_SETUP(ClassSetup)
+        {
+            return true;
+        }
+    };
+
+    void TerminalSettingsTests::TryCreateWinRTType()
+    {
+        TerminalSettings settings;
+        VERIFY_IS_NOT_NULL(settings);
+        auto oldFontSize = settings.FontSize();
+        settings.FontSize(oldFontSize + 5);
+        auto newFontSize = settings.FontSize();
+        VERIFY_ARE_NOT_EQUAL(oldFontSize, newFontSize);
+    }
+
+    void TerminalSettingsTests::TestTerminalArgsForBinding()
+    {
+        const std::string settingsJson{ R"(
+        {
+            "defaultProfile": "{6239a42c-0000-49a3-80bd-e8fdd045185c}",
+            "profiles": [
+                {
+                    "name": "profile0",
+                    "guid": "{6239a42c-0000-49a3-80bd-e8fdd045185c}",
+                    "historySize": 1,
+                    "commandline": "cmd.exe"
+                },
+                {
+                    "name": "profile1",
+                    "guid": "{6239a42c-1111-49a3-80bd-e8fdd045185c}",
+                    "historySize": 2,
+                    "commandline": "pwsh.exe"
+                },
+                {
+                    "name": "profile2",
+                    "historySize": 3,
+                    "commandline": "wsl.exe"
+                }
+            ],
+            "keybindings": [
+                { "keys": ["ctrl+a"], "command": { "action": "splitPane", "split": "vertical" } },
+                { "keys": ["ctrl+b"], "command": { "action": "splitPane", "split": "vertical", "profile": "{6239a42c-1111-49a3-80bd-e8fdd045185c}" } },
+                { "keys": ["ctrl+c"], "command": { "action": "splitPane", "split": "vertical", "profile": "profile1" } },
+                { "keys": ["ctrl+d"], "command": { "action": "splitPane", "split": "vertical", "profile": "profile2" } },
+                { "keys": ["ctrl+e"], "command": { "action": "splitPane", "split": "horizontal", "commandline": "foo.exe" } },
+                { "keys": ["ctrl+f"], "command": { "action": "splitPane", "split": "horizontal", "profile": "profile1", "commandline": "foo.exe" } },
+                { "keys": ["ctrl+g"], "command": { "action": "newTab" } },
+                { "keys": ["ctrl+h"], "command": { "action": "newTab", "startingDirectory": "c:\\foo" } },
+                { "keys": ["ctrl+i"], "command": { "action": "newTab", "profile": "profile2", "startingDirectory": "c:\\foo" } },
+                { "keys": ["ctrl+j"], "command": { "action": "newTab", "tabTitle": "bar" } },
+                { "keys": ["ctrl+k"], "command": { "action": "newTab", "profile": "profile2", "tabTitle": "bar" } },
+                { "keys": ["ctrl+l"], "command": { "action": "newTab", "profile": "profile1", "tabTitle": "bar", "startingDirectory": "c:\\foo", "commandline":"foo.exe" } }
+            ]
+        })" };
+
+        const winrt::guid guid0{ ::Microsoft::Console::Utils::GuidFromString(L"{6239a42c-0000-49a3-80bd-e8fdd045185c}") };
+        const winrt::guid guid1{ ::Microsoft::Console::Utils::GuidFromString(L"{6239a42c-1111-49a3-80bd-e8fdd045185c}") };
+
+        CascadiaSettings settings{ til::u8u16(settingsJson) };
+
+        auto keymap = settings.GlobalSettings().KeyMap();
+        VERIFY_ARE_EQUAL(3u, settings.ActiveProfiles().Size());
+
+        const auto profile2Guid = settings.ActiveProfiles().GetAt(2).Guid();
+        VERIFY_ARE_NOT_EQUAL(winrt::guid{}, profile2Guid);
+
+        VERIFY_ARE_EQUAL(12u, keymap.Size());
+
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('A') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Vertical, realArgs.SplitStyle());
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Profile().empty());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid0, guid);
+            VERIFY_ARE_EQUAL(L"cmd.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(1, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('B') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Vertical, realArgs.SplitStyle());
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"{6239a42c-1111-49a3-80bd-e8fdd045185c}", realArgs.TerminalArgs().Profile());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid1, guid);
+            VERIFY_ARE_EQUAL(L"pwsh.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(2, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('C') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Vertical, realArgs.SplitStyle());
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"profile1", realArgs.TerminalArgs().Profile());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid1, guid);
+            VERIFY_ARE_EQUAL(L"pwsh.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(2, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('D') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Vertical, realArgs.SplitStyle());
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"profile2", realArgs.TerminalArgs().Profile());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(profile2Guid, guid);
+            VERIFY_ARE_EQUAL(L"wsl.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(3, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('E') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Horizontal, realArgs.SplitStyle());
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"foo.exe", realArgs.TerminalArgs().Commandline());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid0, guid);
+            VERIFY_ARE_EQUAL(L"foo.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(1, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('F') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::SplitPane, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<SplitPaneArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_ARE_EQUAL(SplitState::Horizontal, realArgs.SplitStyle());
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"profile1", realArgs.TerminalArgs().Profile());
+            VERIFY_ARE_EQUAL(L"foo.exe", realArgs.TerminalArgs().Commandline());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid1, guid);
+            VERIFY_ARE_EQUAL(L"foo.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(2, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('G') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<NewTabArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Profile().empty());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid0, guid);
+            VERIFY_ARE_EQUAL(L"cmd.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(1, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('H') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<NewTabArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"c:\\foo", realArgs.TerminalArgs().StartingDirectory());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid0, guid);
+            VERIFY_ARE_EQUAL(L"cmd.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(L"c:\\foo", termSettings.StartingDirectory());
+            VERIFY_ARE_EQUAL(1, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('I') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<NewTabArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"c:\\foo", realArgs.TerminalArgs().StartingDirectory());
+            VERIFY_ARE_EQUAL(L"profile2", realArgs.TerminalArgs().Profile());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(profile2Guid, guid);
+            VERIFY_ARE_EQUAL(L"wsl.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(L"c:\\foo", termSettings.StartingDirectory());
+            VERIFY_ARE_EQUAL(3, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('J') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<NewTabArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"bar", realArgs.TerminalArgs().TabTitle());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid0, guid);
+            VERIFY_ARE_EQUAL(L"cmd.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(L"bar", termSettings.StartingTitle());
+            VERIFY_ARE_EQUAL(1, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('K') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<NewTabArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_TRUE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"bar", realArgs.TerminalArgs().TabTitle());
+            VERIFY_ARE_EQUAL(L"profile2", realArgs.TerminalArgs().Profile());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(profile2Guid, guid);
+            VERIFY_ARE_EQUAL(L"wsl.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(L"bar", termSettings.StartingTitle());
+            VERIFY_ARE_EQUAL(3, termSettings.HistorySize());
+        }
+        {
+            KeyChord kc{ true, false, false, static_cast<int32_t>('L') };
+            auto actionAndArgs = ::TestUtils::GetActionAndArgs(keymap, kc);
+            VERIFY_ARE_EQUAL(ShortcutAction::NewTab, actionAndArgs.Action());
+            const auto& realArgs = actionAndArgs.Args().try_as<NewTabArgs>();
+            VERIFY_IS_NOT_NULL(realArgs);
+            // Verify the args have the expected value
+            VERIFY_IS_NOT_NULL(realArgs.TerminalArgs());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Commandline().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().StartingDirectory().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().TabTitle().empty());
+            VERIFY_IS_FALSE(realArgs.TerminalArgs().Profile().empty());
+            VERIFY_ARE_EQUAL(L"foo.exe", realArgs.TerminalArgs().Commandline());
+            VERIFY_ARE_EQUAL(L"c:\\foo", realArgs.TerminalArgs().StartingDirectory());
+            VERIFY_ARE_EQUAL(L"bar", realArgs.TerminalArgs().TabTitle());
+            VERIFY_ARE_EQUAL(L"profile1", realArgs.TerminalArgs().Profile());
+
+            const auto guid{ settings.GetProfileForArgs(realArgs.TerminalArgs()) };
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, realArgs.TerminalArgs(), nullptr) };
+            VERIFY_ARE_EQUAL(guid1, guid);
+            VERIFY_ARE_EQUAL(L"foo.exe", termSettings.Commandline());
+            VERIFY_ARE_EQUAL(L"bar", termSettings.StartingTitle());
+            VERIFY_ARE_EQUAL(L"c:\\foo", termSettings.StartingDirectory());
+            VERIFY_ARE_EQUAL(2, termSettings.HistorySize());
+        }
+    }
+
+    void TerminalSettingsTests::MakeSettingsForProfileThatDoesntExist()
+    {
+        // Test that making settings throws when the GUID doesn't exist
+        const std::string settingsString{ R"(
+        {
+            "defaultProfile": "{6239a42c-1111-49a3-80bd-e8fdd045185c}",
+            "profiles": [
+                {
+                    "name" : "profile0",
+                    "guid": "{6239a42c-1111-49a3-80bd-e8fdd045185c}",
+                    "historySize": 1
+                },
+                {
+                    "name" : "profile1",
+                    "guid": "{6239a42c-2222-49a3-80bd-e8fdd045185c}",
+                    "historySize": 2
+                }
+            ]
+        })" };
+        CascadiaSettings settings{ til::u8u16(settingsString) };
+
+        const auto guid1 = ::Microsoft::Console::Utils::GuidFromString(L"{6239a42c-1111-49a3-80bd-e8fdd045185c}");
+        const auto guid2 = ::Microsoft::Console::Utils::GuidFromString(L"{6239a42c-2222-49a3-80bd-e8fdd045185c}");
+        const auto guid3 = ::Microsoft::Console::Utils::GuidFromString(L"{6239a42c-3333-49a3-80bd-e8fdd045185c}");
+
+        try
+        {
+            auto terminalSettings{ TerminalSettings::CreateWithProfileByID(settings, guid1, nullptr) };
+            VERIFY_ARE_NOT_EQUAL(nullptr, terminalSettings);
+            VERIFY_ARE_EQUAL(1, terminalSettings.HistorySize());
+        }
+        catch (...)
+        {
+            VERIFY_IS_TRUE(false, L"This call to CreateWithProfileByID should succeed");
+        }
+
+        try
+        {
+            auto terminalSettings{ TerminalSettings::CreateWithProfileByID(settings, guid2, nullptr) };
+            VERIFY_ARE_NOT_EQUAL(nullptr, terminalSettings);
+            VERIFY_ARE_EQUAL(2, terminalSettings.HistorySize());
+        }
+        catch (...)
+        {
+            VERIFY_IS_TRUE(false, L"This call to CreateWithProfileByID should succeed");
+        }
+
+        VERIFY_THROWS(auto terminalSettings = TerminalSettings::CreateWithProfileByID(settings, guid3, nullptr), wil::ResultException, L"This call to constructor should fail");
+
+        try
+        {
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, nullptr, nullptr) };
+            VERIFY_ARE_NOT_EQUAL(nullptr, termSettings);
+            VERIFY_ARE_EQUAL(1, termSettings.HistorySize());
+        }
+        catch (...)
+        {
+            VERIFY_IS_TRUE(false, L"This call to CreateWithNewTerminalArgs should succeed");
+        }
+    }
+
+    void TerminalSettingsTests::MakeSettingsForDefaultProfileThatDoesntExist()
+    {
+        // Test that MakeSettings _doesnt_ throw when we load settings with a
+        // defaultProfile that's not in the list, we validate the settings, and
+        // then call MakeSettings(nullopt). The validation should ensure that
+        // the default profile is something reasonable
+        const std::string settingsString{ R"(
+        {
+            "defaultProfile": "{6239a42c-3333-49a3-80bd-e8fdd045185c}",
+            "profiles": [
+                {
+                    "name" : "profile0",
+                    "guid": "{6239a42c-1111-49a3-80bd-e8fdd045185c}",
+                    "historySize": 1
+                },
+                {
+                    "name" : "profile1",
+                    "guid": "{6239a42c-2222-49a3-80bd-e8fdd045185c}",
+                    "historySize": 2
+                }
+            ]
+        })" };
+        CascadiaSettings settings{ til::u8u16(settingsString) };
+
+        VERIFY_ARE_EQUAL(2u, settings.Warnings().Size());
+        VERIFY_ARE_EQUAL(2u, settings.ActiveProfiles().Size());
+        VERIFY_ARE_EQUAL(settings.GlobalSettings().DefaultProfile(), settings.ActiveProfiles().GetAt(0).Guid());
+        try
+        {
+            const auto termSettings{ TerminalSettings::CreateWithNewTerminalArgs(settings, nullptr, nullptr) };
+            VERIFY_ARE_NOT_EQUAL(nullptr, termSettings);
+            VERIFY_ARE_EQUAL(1, termSettings.HistorySize());
+        }
+        catch (...)
+        {
+            VERIFY_IS_TRUE(false, L"This call to CreateWithNewTerminalArgs should succeed");
+        }
+    }
+
+    void TerminalSettingsTests::TestLayerProfileOnColorScheme()
+    {
+        Log::Comment(NoThrowString().Format(
+            L"Ensure that setting (or not) a property in the profile that should override a property of the color scheme works correctly."));
+
+        const std::string settings0String{ R"(
+        {
+            "defaultProfile": "profile5",
+            "profiles": [
+                {
+                    "name" : "profile0",
+                    "colorScheme": "schemeWithCursorColor"
+                },
+                {
+                    "name" : "profile1",
+                    "colorScheme": "schemeWithoutCursorColor"
+                },
+                {
+                    "name" : "profile2",
+                    "colorScheme": "schemeWithCursorColor",
+                    "cursorColor": "#234567"
+                },
+                {
+                    "name" : "profile3",
+                    "colorScheme": "schemeWithoutCursorColor",
+                    "cursorColor": "#345678"
+                },
+                {
+                    "name" : "profile4",
+                    "cursorColor": "#456789"
+                },
+                {
+                    "name" : "profile5"
+                }
+            ],
+            "schemes": [
+                {
+                    "name": "schemeWithCursorColor",
+                    "cursorColor": "#123456"
+                },
+                {
+                    "name": "schemeWithoutCursorColor"
+                }
+            ]
+        })" };
+
+        CascadiaSettings settings{ til::u8u16(settings0String) };
+
+        VERIFY_ARE_EQUAL(6u, settings.ActiveProfiles().Size());
+        VERIFY_ARE_EQUAL(2u, settings.GlobalSettings().ColorSchemes().Size());
+
+        auto createTerminalSettings = [&](const auto& profile, const auto& schemes) {
+            auto terminalSettings{ winrt::make_self<implementation::TerminalSettings>() };
+            terminalSettings->_ApplyProfileSettings(profile, schemes);
+            return terminalSettings;
+        };
+
+        auto terminalSettings0 = createTerminalSettings(settings.ActiveProfiles().GetAt(0), settings.GlobalSettings().ColorSchemes());
+        auto terminalSettings1 = createTerminalSettings(settings.ActiveProfiles().GetAt(1), settings.GlobalSettings().ColorSchemes());
+        auto terminalSettings2 = createTerminalSettings(settings.ActiveProfiles().GetAt(2), settings.GlobalSettings().ColorSchemes());
+        auto terminalSettings3 = createTerminalSettings(settings.ActiveProfiles().GetAt(3), settings.GlobalSettings().ColorSchemes());
+        auto terminalSettings4 = createTerminalSettings(settings.ActiveProfiles().GetAt(4), settings.GlobalSettings().ColorSchemes());
+        auto terminalSettings5 = createTerminalSettings(settings.ActiveProfiles().GetAt(5), settings.GlobalSettings().ColorSchemes());
+
+        VERIFY_ARE_EQUAL(ARGB(0, 0x12, 0x34, 0x56), terminalSettings0->CursorColor()); // from color scheme
+        VERIFY_ARE_EQUAL(DEFAULT_CURSOR_COLOR, terminalSettings1->CursorColor()); // default
+        VERIFY_ARE_EQUAL(ARGB(0, 0x23, 0x45, 0x67), terminalSettings2->CursorColor()); // from profile (trumps color scheme)
+        VERIFY_ARE_EQUAL(ARGB(0, 0x34, 0x56, 0x78), terminalSettings3->CursorColor()); // from profile (not set in color scheme)
+        VERIFY_ARE_EQUAL(ARGB(0, 0x45, 0x67, 0x89), terminalSettings4->CursorColor()); // from profile (no color scheme)
+        VERIFY_ARE_EQUAL(DEFAULT_CURSOR_COLOR, terminalSettings5->CursorColor()); // default
+    }
+}