Reimplement DECPS using DirectSound in place of MIDI (#13471)

## Summary of the Pull Request

The original `DECPS` implementation made use of the Windows MIDI APIs to
generate the sound, but that required a 3MB package dependency for the
GS wavetable DLS. This PR reimplements the `MidiAudio` class using
`DirectSound`, so we can avoid that dependency.

## References

The original `DECPS` implementation was added in PR #13208, but was
hidden behind a velocity flag in #13258.

## PR Checklist
* [x] Closes #13252
* [x] CLA signed.
* [ ] Tests added/passed
* [ ] Documentation updated.
* [ ] Schema updated.
* [x] I've discussed this with core contributors already. Issue number
where discussion took place: #13252

## Detailed Description of the Pull Request / Additional comments

The way it works is by creating a sound buffer with a single triangle
wave that is played in a loop. We generate different notes simply by
adjusting the frequency at which that buffer is played.

When we need a note to end, we just set the volume to its minimum value
rather than stopping the buffer. If we don't do that, the repeated
starting and stopping tends to produce a lot of static in the output. We
also use two buffers, which we alternate between notes, as another way
to reduce that static.

One other thing worth mentioning is the handling of the buffer position.
At the end of each note we save the current position, and then use an
offset from that position when starting the following note. This helps
produce a clearer separation between tones when repeating sequences of
the same note.

In an ideal world, we should really have something like an attack-decay-
sustain-release envelope for each note, but the above hack seems to work
reasonably well, and keeps the implementation simple.

## Validation Steps Performed

I've manually tested both conhost and Terminal with the sample tunes
listed in issue #8687, as well as a couple of games that I have which
make use of `DECPS` sound effects.

(cherry picked from commit bc79867b38)
Service-Card-Id: 84270205
Service-Version: 1.15

.github/actions/spelling/expect/expect.txt

@@ -438,7 +438,9 @@ ctlseqs
 Ctlv
 ctor
 CTRLEVENT
+CTRLFREQUENCY
 CTRLKEYSHORTCUTS
+CTRLVOLUME
 Ctx
 Ctxt
 ctype
@@ -661,7 +663,14 @@ dropdown
 DROPDOWNLIST
 DROPFILES
 drv
+DSBCAPS
+DSBLOCK
+DSBPLAY
+DSBUFFERDESC
+DSBVOLUME
 dsm
+dsound
+DSSCL
 dst
 DSwap
 DTest
@@ -682,6 +691,7 @@ dwrite
 dwriteglyphrundescriptionclustermap
 dxgi
 dxgidwm
+dxguid
 dxinterop
 dxp
 dxsm
@@ -718,6 +728,7 @@ endptr
 endregion
 ENQ
 enqueuing
+ENTIREBUFFER
 entrypoint
 ENU
 enum
@@ -934,6 +945,7 @@ gitfilters
 github
 gitlab
 gle
+GLOBALFOCUS
 globals
 GLYPHENTRY
 gmail
@@ -1369,6 +1381,7 @@ lpv
 LPVOID
 LPW
 LPWCH
+lpwfx
 LPWINDOWPOS
 lpwpos
 lpwstr
@@ -2678,6 +2691,7 @@ WANTARROWS
 WANTTAB
 wapproj
 wav
+WAVEFORMATEX
 wbuilder
 wch
 wchar

doc/cascadia/profiles.schema.json

@@ -366,6 +366,10 @@
         "quit",
         "adjustOpacity",
         "restoreLastClosed",
+        "addMark",
+        "scrollToMark",
+        "clearMark",
+        "clearAllMarks",
         "unbound"
       ],
       "type": "string"
@@ -385,6 +389,15 @@
       ],
       "type": "string"
     },
+    "ScrollToMarkDirection": {
+      "enum": [
+        "previous",
+        "next",
+        "first",
+        "last"
+      ],
+      "type": "string"
+    },
     "ResizeDirection": {
       "enum": [
         "left",
@@ -734,6 +747,30 @@
         "direction"
       ]
     },
+    "ScrollToMarkAction": {
+      "description": "Arguments corresponding to a Scroll to Mark Action",
+      "allOf": [
+        {
+          "$ref": "#/$defs/ShortcutAction"
+        },
+        {
+          "properties": {
+            "action": {
+              "type": "string",
+              "const": "scrollToMark"
+            },
+            "direction": {
+              "$ref": "#/$defs/ScrollToMarkDirection",
+              "default": "previous",
+              "description": "The direction to scroll to a mark."
+            }
+          }
+        }
+      ],
+      "required": [
+        "direction"
+      ]
+    },
     "SendInputAction": {
       "description": "Arguments corresponding to a Send Input Action",
       "allOf": [
@@ -841,6 +878,27 @@
         }
       ]
     },
+    "AddMarkAction": {
+      "description": "Arguments corresponding to an Add Mark Action",
+      "allOf": [
+        {
+          "$ref": "#/$defs/ShortcutAction"
+        },
+        {
+          "properties": {
+            "action": {
+              "type": "string",
+              "const": "addMark"
+            },
+            "color": {
+              "$ref": "#/$defs/Color",
+              "default": null,
+              "description": "If provided, will set the mark's color to the given value."
+            }
+          }
+        }
+      ]
+    },
     "SetColorSchemeAction": {
       "description": "Arguments corresponding to a Set Color Scheme Action",
       "allOf": [
@@ -1669,6 +1727,16 @@
           "description": "When set to true, URLs will be detected by the Terminal. This will cause URLs to underline on hover and be clickable by pressing Ctrl.",
           "type": "boolean"
         },
+        "experimental.autoMarkPrompts": {
+          "default": false,
+          "description": "When set to true, prompts will automatically be marked.",
+          "type": "boolean"
+        },
+        "experimental.showMarksOnScrollbar": {
+          "default": false,
+          "description": "When set to true, marks added to the buffer via the addMark action will appear on the scrollbar.",
+          "type": "boolean"
+        },
         "disableAnimations": {
           "default": false,
           "description": "When set to `true`, visual animations will be disabled across the application.",
@@ -2013,6 +2081,10 @@
           "description": "Controls what happens when the application emits a BEL character. When set to \"all\", the Terminal will play a sound, flash the taskbar icon (if the terminal window is not in focus) and flash the window. An array of specific behaviors can also be used. Supported array values include `audible`, `window` and `taskbar`. When set to \"none\", nothing will happen.",
           "$ref": "#/$defs/BellStyle"
         },
+        "bellSound": {
+          "description": "Sets the sound played when the application emits a BEL. When set to an array, the terminal will pick one of those sounds at random.",
+          "$ref": "#/$defs/BellSound"
+        },
         "closeOnExit": {
           "default": "graceful",
           "description": "Sets how the profile reacts to termination or failure to launch. Possible values:\n -\"graceful\" (close when exit is typed or the process exits normally)\n -\"always\" (always close)\n -\"never\" (never close).\ntrue and false are accepted as synonyms for \"graceful\" and \"never\" respectively.",

src/audio/midi/MidiAudio.cpp

@@ -5,55 +5,30 @@
 #include "MidiAudio.hpp"
 #include "../terminal/parser/stateMachine.hpp"
 
-namespace
-{
-    class MidiOut
-    {
-    public:
-        static constexpr auto NOTE_OFF = 0x80;
-        static constexpr auto NOTE_ON = 0x90;
-        static constexpr auto PROGRAM_CHANGE = 0xC0;
+#include <dsound.h>
 
-        // We're using a square wave as an approximation of the sound that the
-        // original VT525 terminals might have produced. This is probably not
-        // quite right, but it works reasonably well.
-        static constexpr auto SQUARE_WAVE_SYNTH = 80;
-
-        MidiOut() noexcept
-        {
-            if constexpr (Feature_DECPSViaMidiPlayer::IsEnabled())
-            {
-                midiOutOpen(&handle, MIDI_MAPPER, NULL, NULL, CALLBACK_NULL);
-                OutputMessage(PROGRAM_CHANGE, SQUARE_WAVE_SYNTH);
-            }
-        }
-        ~MidiOut() noexcept
-        {
-            if constexpr (Feature_DECPSViaMidiPlayer::IsEnabled())
-            {
-                midiOutClose(handle);
-            }
-        }
-        void OutputMessage(const int b1, const int b2, const int b3 = 0, const int b4 = 0) noexcept
-        {
-            if constexpr (Feature_DECPSViaMidiPlayer::IsEnabled())
-            {
-                midiOutShortMsg(handle, MAKELONG(MAKEWORD(b1, b2), MAKEWORD(b3, b4)));
-            }
-        }
-
-        MidiOut(const MidiOut&) = delete;
-        MidiOut(MidiOut&&) = delete;
-        MidiOut& operator=(const MidiOut&) = delete;
-        MidiOut& operator=(MidiOut&&) = delete;
-
-    private:
-        HMIDIOUT handle = nullptr;
-    };
-}
+#pragma comment(lib, "dxguid.lib")
+#pragma comment(lib, "dsound.lib")
 
+using Microsoft::WRL::ComPtr;
 using namespace std::chrono_literals;
 
+// The WAVE_DATA below is an 8-bit PCM encoding of a triangle wave form.
+// We just play this on repeat at varying frequencies to produce our notes.
+constexpr auto WAVE_SIZE = 16u;
+constexpr auto WAVE_DATA = std::array<byte, WAVE_SIZE>{ 128, 159, 191, 223, 255, 223, 191, 159, 128, 96, 64, 32, 0, 32, 64, 96 };
+
+MidiAudio::MidiAudio(HWND windowHandle)
+{
+    if (SUCCEEDED(DirectSoundCreate8(nullptr, &_directSound, nullptr)))
+    {
+        if (SUCCEEDED(_directSound->SetCooperativeLevel(windowHandle, DSSCL_NORMAL)))
+        {
+            _createBuffers();
+        }
+    }
+}
+
 MidiAudio::~MidiAudio() noexcept
 {
     try
@@ -61,7 +36,7 @@ MidiAudio::~MidiAudio() noexcept
 #pragma warning(suppress : 26447)
         // We acquire the lock here so the class isn't destroyed while in use.
         // If this throws, we'll catch it, so the C26447 warning is bogus.
-        _inUseMutex.lock();
+        const auto lock = std::unique_lock{ _inUseMutex };
     }
     catch (...)
     {
@@ -103,13 +78,26 @@ void MidiAudio::Unlock()
 void MidiAudio::PlayNote(const int noteNumber, const int velocity, const std::chrono::microseconds duration) noexcept
 try
 {
-    // The MidiOut is a local static because we can only have one instance,
-    // and we only want to construct it when it's actually needed.
-    static MidiOut midiOut;
-
-    if (velocity)
+    const auto& buffer = _buffers.at(_activeBufferIndex);
+    if (velocity && buffer)
     {
-        midiOut.OutputMessage(MidiOut::NOTE_ON, noteNumber, velocity);
+        // The formula for frequency is 2^(n/12) * 440Hz, where n is zero for
+        // the A above middle C (A4). In MIDI terms, A4 is note number 69,
+        // which is why we subtract 69. We also need to multiply by the size
+        // of the wave form to determine the frequency that the sound buffer
+        // has to be played to achieve the equivalent note frequency.
+        const auto frequency = std::pow(2.0, (noteNumber - 69.0) / 12.0) * 440.0 * WAVE_SIZE;
+        buffer->SetFrequency(gsl::narrow_cast<DWORD>(frequency));
+        // For the volume, we're using the formula defined in the the General
+        // MIDI Level 2 specification: Gain in dB = 40 * log10(v/127). We need
+        // to multiply by 4000, though, because the SetVolume method expects
+        // the volume to be in hundredths of a decibel.
+        const auto volume = 4000.0 * std::log10(velocity / 127.0);
+        buffer->SetVolume(gsl::narrow_cast<LONG>(volume));
+        // Resetting the buffer to a position that is slightly off from the
+        // last position will help to produce a clearer separation between
+        // tones when repeating sequences of the same note.
+        buffer->SetCurrentPosition((_lastBufferPosition + 12) % WAVE_SIZE);
     }
 
     // By waiting on the shutdown future with the duration of the note, we'll
@@ -117,9 +105,48 @@ try
     // of the wait early if we've been shutdown.
     _shutdownFuture.wait_for(duration);
 
-    if (velocity)
+    if (velocity && buffer)
     {
-        midiOut.OutputMessage(MidiOut::NOTE_OFF, noteNumber, velocity);
+        // When the note ends, we just turn the volume down instead of stopping
+        // the sound buffer. This helps reduce unwanted static between notes.
+        buffer->SetVolume(DSBVOLUME_MIN);
+        buffer->GetCurrentPosition(&_lastBufferPosition, nullptr);
     }
+
+    // Cycling between multiple buffers can also help reduce the static.
+    _activeBufferIndex = (_activeBufferIndex + 1) % _buffers.size();
 }
 CATCH_LOG()
+
+void MidiAudio::_createBuffers() noexcept
+{
+    auto waveFormat = WAVEFORMATEX{};
+    waveFormat.wFormatTag = WAVE_FORMAT_PCM;
+    waveFormat.nChannels = 1;
+    waveFormat.nSamplesPerSec = 8000;
+    waveFormat.wBitsPerSample = 8;
+    waveFormat.nBlockAlign = waveFormat.nChannels * waveFormat.wBitsPerSample / 8;
+    waveFormat.nAvgBytesPerSec = waveFormat.nSamplesPerSec * waveFormat.nBlockAlign;
+
+    auto bufferDescription = DSBUFFERDESC{};
+    bufferDescription.dwSize = sizeof(DSBUFFERDESC);
+    bufferDescription.dwFlags = DSBCAPS_CTRLVOLUME | DSBCAPS_CTRLFREQUENCY | DSBCAPS_GLOBALFOCUS;
+    bufferDescription.dwBufferBytes = WAVE_SIZE;
+    bufferDescription.lpwfxFormat = &waveFormat;
+
+    for (auto& buffer : _buffers)
+    {
+        if (SUCCEEDED(_directSound->CreateSoundBuffer(&bufferDescription, &buffer, nullptr)))
+        {
+            LPVOID bufferPtr;
+            DWORD bufferSize;
+            if (SUCCEEDED(buffer->Lock(0, 0, &bufferPtr, &bufferSize, nullptr, nullptr, DSBLOCK_ENTIREBUFFER)))
+            {
+                std::memcpy(bufferPtr, WAVE_DATA.data(), WAVE_DATA.size());
+                buffer->Unlock(bufferPtr, bufferSize, nullptr, 0);
+            }
+            buffer->SetVolume(DSBVOLUME_MIN);
+            buffer->Play(0, 0, DSBPLAY_LOOPING);
+        }
+    }
+}

src/audio/midi/MidiAudio.hpp

@@ -11,13 +11,17 @@ Abstract:
 
 #pragma once
 
+#include <array>
 #include <future>
 #include <mutex>
 
+struct IDirectSound8;
+struct IDirectSoundBuffer;
+
 class MidiAudio
 {
 public:
-    MidiAudio() = default;
+    MidiAudio(HWND windowHandle);
     MidiAudio(const MidiAudio&) = delete;
     MidiAudio(MidiAudio&&) = delete;
     MidiAudio& operator=(const MidiAudio&) = delete;
@@ -30,6 +34,12 @@ public:
     void PlayNote(const int noteNumber, const int velocity, const std::chrono::microseconds duration) noexcept;
 
 private:
+    void _createBuffers() noexcept;
+
+    Microsoft::WRL::ComPtr<IDirectSound8> _directSound;
+    std::array<Microsoft::WRL::ComPtr<IDirectSoundBuffer>, 2> _buffers;
+    size_t _activeBufferIndex = 0;
+    DWORD _lastBufferPosition = 0;
     std::promise<void> _shutdownPromise;
     std::future<void> _shutdownFuture;
     std::mutex _inUseMutex;

src/cascadia/TerminalApp/AppLogic.cpp

@@ -292,7 +292,7 @@ namespace winrt::TerminalApp::implementation
                 _root->Maximized(true);
             }
 
-            if (WI_IsFlagSet(launchMode, LaunchMode::FullscreenMode))
+            if (WI_IsFlagSet(launchMode, LaunchMode::FullscreenMode) && !IsQuakeWindow())
             {
                 _root->SetFullscreen(true);
             }

src/cascadia/TerminalApp/DebugTapConnection.cpp

@@ -111,7 +111,15 @@ namespace winrt::Microsoft::TerminalApp::implementation
 
     void DebugTapConnection::_OutputHandler(const hstring str)
     {
-        _TerminalOutputHandlers(til::visualize_control_codes(str));
+        auto output = til::visualize_control_codes(str);
+        // To make the output easier to read, we introduce a line break whenever
+        // an LF control is encountered. But at this point, the LF would have
+        // been converted to U+240A (␊), so that's what we need to search for.
+        for (size_t lfPos = 0; (lfPos = output.find(L'\u240A', lfPos)) != std::wstring::npos;)
+        {
+            output.insert(++lfPos, L"\r\n");
+        }
+        _TerminalOutputHandlers(output);
     }
 
     // Called by the DebugInputTapConnection to print user input

src/cascadia/TerminalApp/TabRowControl.xaml

@@ -60,7 +60,8 @@
                                  FontSize="12">
                     <ToolTipService.ToolTip>
                         <ToolTip Placement="Mouse">
-                            <TextBlock IsTextSelectionEnabled="False">
+                            <TextBlock IsTextSelectionEnabled="False"
+                                       TextWrapping="Wrap">
                                 <Run x:Uid="NewTabRun" /> <LineBreak />
                                 <Run x:Uid="NewPaneRun"
                                      FontStyle="Italic" /> <LineBreak />

src/cascadia/TerminalApp/TerminalTab.cpp

@@ -1452,18 +1452,16 @@ namespace winrt::TerminalApp::implementation
             subtleFillColorTertiaryBrush.Color(subtleFillColorTertiary);
         }
 
-        hoverTabBrush.Color(TerminalApp::ColorHelper::GetAccentColor(color));
         selectedTabBrush.Color(color);
 
         // currently if a tab has a custom color, a deselected state is
         // signified by using the same color with a bit of transparency
-        auto deselectedTabColor = color;
-        deselectedTabColor.A = 64;
-        deselectedTabBrush.Color(deselectedTabColor);
+        deselectedTabBrush.Color(color);
+        deselectedTabBrush.Opacity(0.3);
+
+        hoverTabBrush.Color(color);
+        hoverTabBrush.Opacity(0.6);
 
-        // currently if a tab has a custom color, a deselected state is
-        // signified by using the same color with a bit of transparency
-        //
         // Prior to MUX 2.7, we set TabViewItemHeaderBackground, but now we can
         // use TabViewItem().Background() for that. HOWEVER,
         // TabViewItem().Background() only sets the color of the tab background

src/cascadia/TerminalConnection/CTerminalHandoff.cpp

@@ -53,7 +53,12 @@ CATCH_RETURN()
 HRESULT CTerminalHandoff::s_StopListening()
 {
     std::unique_lock lock{ _mtx };
+    return s_StopListeningLocked();
+}
 
+// See s_StopListening()
+HRESULT CTerminalHandoff::s_StopListeningLocked()
+{
     RETURN_HR_IF_NULL(E_NOT_VALID_STATE, _pfnHandoff);
 
     _pfnHandoff = nullptr;
@@ -101,14 +106,16 @@ HRESULT CTerminalHandoff::EstablishPtyHandoff(HANDLE in, HANDLE out, HANDLE sign
 {
     try
     {
-        // Stash a local copy of _pfnHandoff before we stop listening.
+        std::unique_lock lock{ _mtx };
+
+        // s_StopListeningLocked sets _pfnHandoff to nullptr.
+        // localPfnHandoff is tested for nullness below.
+#pragma warning(suppress : 26429) // Symbol '...' is never tested for nullness, it can be marked as not_null (f.23).
         auto localPfnHandoff = _pfnHandoff;
 
         // Because we are REGCLS_SINGLEUSE... we need to `CoRevokeClassObject` after we handle this ONE call.
         // COM does not automatically clean that up for us. We must do it.
-        s_StopListening();
-
-        std::unique_lock lock{ _mtx };
+        LOG_IF_FAILED(s_StopListeningLocked());
 
         // Report an error if no one registered a handoff function before calling this.
         THROW_HR_IF_NULL(E_NOT_VALID_STATE, localPfnHandoff);

src/cascadia/TerminalConnection/CTerminalHandoff.h

@@ -43,6 +43,9 @@ struct __declspec(uuid(__CLSID_CTerminalHandoff))
 
     static HRESULT s_StartListening(NewHandoffFunction pfnHandoff);
     static HRESULT s_StopListening();
+
+private:
+    static HRESULT s_StopListeningLocked();
 };
 
 // Disable warnings from the CoCreatableClass macro as the value it provides for

src/cascadia/TerminalControl/ControlCore.cpp

@@ -1094,6 +1094,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         if (_terminal->IsSelectionActive())
         {
             _terminal->SwitchSelectionEndpoint();
+            _updateSelectionUI();
             return true;
         }
         return false;
@@ -1341,7 +1342,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     {
         if (!_midiAudio)
         {
-            _midiAudio = std::make_unique<MidiAudio>();
+            const auto windowHandle = reinterpret_cast<HWND>(_owningHwnd);
+            _midiAudio = std::make_unique<MidiAudio>(windowHandle);
             _midiAudio->Initialize();
         }
         return *_midiAudio;
@@ -1911,13 +1913,24 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     // - This is related to work done for GH#2988.
     void ControlCore::GotFocus()
     {
-        _terminal->FocusChanged(true);
+        _focusChanged(true);
     }
 
     // See GotFocus.
     void ControlCore::LostFocus()
     {
-        _terminal->FocusChanged(false);
+        _focusChanged(false);
+    }
+
+    void ControlCore::_focusChanged(bool focused)
+    {
+        // GH#13461 - temporarily turn off read-only mode, send the focus event,
+        // then turn it back on. Even in focus mode, focus events are fine to
+        // send. We don't want to pop a warning every time the control is
+        // focused.
+        const auto previous = std::exchange(_isReadOnly, false);
+        const auto restore = wil::scope_exit([&]() { _isReadOnly = previous; });
+        _terminal->FocusChanged(focused);
     }
 
     bool ControlCore::_isBackgroundTransparent()

src/cascadia/TerminalControl/ControlCore.h

@@ -311,6 +311,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void _setOpacity(const double opacity);
 
         bool _isBackgroundTransparent();
+        void _focusChanged(bool focused);
 
         inline bool _IsClosing() const noexcept
         {

src/cascadia/TerminalControl/TermControl.cpp

@@ -432,12 +432,14 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             // achieve the intended effect.
             ScrollBar().IndicatorMode(Controls::Primitives::ScrollingIndicatorMode::None);
             ScrollBar().Visibility(Visibility::Collapsed);
+            ScrollMarksGrid().Visibility(Visibility::Collapsed);
         }
         else // (default or Visible)
         {
             // Default behavior
             ScrollBar().IndicatorMode(Controls::Primitives::ScrollingIndicatorMode::MouseIndicator);
             ScrollBar().Visibility(Visibility::Visible);
+            ScrollMarksGrid().Visibility(Visibility::Visible);
         }
 
         _interactivity.UpdateSettings();

src/cascadia/TerminalControl/TerminalControlLib.vcxproj

@@ -147,10 +147,6 @@
     <PRIResource Include="Resources\en-US\Resources.resw" />
     <OCResourceDirectory Include="Resources" />
   </ItemGroup>
-  <ItemGroup Condition="'$(WindowsTerminalBranding)'=='' or '$(WindowsTerminalBranding)'=='Dev' or '$(WindowsTerminalBranding)'=='Preview'">
-    <!-- GH#13252 Only vend this dependency for Dev and Preview builds. -->
-    <SDKReference Include="Microsoft.Midi.GmDls, Version=10.0.22000.0" />
-  </ItemGroup>
   <!-- ========================= Project References ======================== -->
   <ItemGroup>
     <ProjectReference Include="..\..\types\lib\types.vcxproj" />

src/cascadia/TerminalSettingsModel/WslDistroGenerator.cpp

@@ -7,8 +7,6 @@
 #include "LegacyProfileGeneratorNamespaces.h"
 #include "../../inc/DefaultSettings.h"
 
-#include <io.h>
-#include <fcntl.h>
 #include "DynamicProfileUtils.h"
 
 static constexpr std::wstring_view WslHomeDirectory{ L"~" };
@@ -68,105 +66,6 @@ static winrt::com_ptr<implementation::Profile> makeProfile(const std::wstring& d
     return WSLDistro;
 }
 
-// Method Description:
-// -  Enumerates all the installed WSL distros to create profiles for them.
-// Arguments:
-// - <none>
-// Return Value:
-// - a vector with all distros for all the installed WSL distros
-static void legacyGenerate(std::vector<winrt::com_ptr<implementation::Profile>>& profiles)
-{
-    wil::unique_handle readPipe;
-    wil::unique_handle writePipe;
-    SECURITY_ATTRIBUTES sa{ sizeof(sa), nullptr, true };
-    THROW_IF_WIN32_BOOL_FALSE(CreatePipe(&readPipe, &writePipe, &sa, 0));
-    STARTUPINFO si{ 0 };
-    si.cb = sizeof(si);
-    si.dwFlags = STARTF_USESTDHANDLES;
-    si.hStdOutput = writePipe.get();
-    si.hStdError = writePipe.get();
-    wil::unique_process_information pi;
-    wil::unique_cotaskmem_string systemPath;
-    THROW_IF_FAILED(wil::GetSystemDirectoryW(systemPath));
-    std::wstring command(systemPath.get());
-    command += L"\\wsl.exe --list";
-
-    THROW_IF_WIN32_BOOL_FALSE(CreateProcessW(nullptr,
-                                             const_cast<LPWSTR>(command.c_str()),
-                                             nullptr,
-                                             nullptr,
-                                             TRUE,
-                                             CREATE_NO_WINDOW,
-                                             nullptr,
-                                             nullptr,
-                                             &si,
-                                             &pi));
-    switch (WaitForSingleObject(pi.hProcess, 2000))
-    {
-    case WAIT_OBJECT_0:
-        break;
-    case WAIT_ABANDONED:
-    case WAIT_TIMEOUT:
-        return;
-    case WAIT_FAILED:
-        THROW_LAST_ERROR();
-    default:
-        THROW_HR(ERROR_UNHANDLED_EXCEPTION);
-    }
-    DWORD exitCode;
-    if (!GetExitCodeProcess(pi.hProcess, &exitCode))
-    {
-        THROW_HR(E_INVALIDARG);
-    }
-    else if (exitCode != 0)
-    {
-        return;
-    }
-    DWORD bytesAvailable;
-    THROW_IF_WIN32_BOOL_FALSE(PeekNamedPipe(readPipe.get(), nullptr, NULL, nullptr, &bytesAvailable, nullptr));
-    // "The _open_osfhandle call transfers ownership of the Win32 file handle to the file descriptor."
-    // (https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/open-osfhandle?view=vs-2019)
-    // so, we detach_from_smart_pointer it -- but...
-    // "File descriptors passed into _fdopen are owned by the returned FILE * stream.
-    // If _fdopen is successful, do not call _close on the file descriptor.
-    // Calling fclose on the returned FILE * also closes the file descriptor."
-    // https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/fdopen-wfdopen?view=vs-2019
-    auto stdioPipeHandle = _wfdopen(_open_osfhandle((intptr_t)wil::detach_from_smart_pointer(readPipe), _O_WTEXT | _O_RDONLY), L"r");
-    auto closeFile = wil::scope_exit([&]() { fclose(stdioPipeHandle); });
-
-    std::wfstream pipe{ stdioPipeHandle };
-
-    std::wstring wline;
-    std::getline(pipe, wline); // remove the header from the output.
-    while (pipe.tellp() < bytesAvailable)
-    {
-        std::getline(pipe, wline);
-        std::wstringstream wlinestream(wline);
-        if (wlinestream)
-        {
-            std::wstring distName;
-            std::getline(wlinestream, distName, L'\r');
-
-            if (til::starts_with(distName, DockerDistributionPrefix))
-            {
-                // Docker for Windows creates some utility distributions to handle Docker commands.
-                // Pursuant to GH#3556, because they are _not_ user-facing we want to hide them.
-                continue;
-            }
-
-            const auto firstChar = distName.find_first_of(L"( ");
-            // Some localizations don't have a space between the name and "(Default)"
-            // https://github.com/microsoft/terminal/issues/1168#issuecomment-500187109
-            if (firstChar < distName.size())
-            {
-                distName.resize(firstChar);
-            }
-
-            profiles.emplace_back(makeProfile(distName));
-        }
-    }
-}
-
 // Function Description:
 // - Create a list of Profiles for each distro listed in names.
 // - Skips distros that are utility distros for docker (see GH#3556)
@@ -310,9 +209,9 @@ static bool getWslNames(const wil::unique_hkey& wslRootKey,
 // Method Description:
 // - Generate a list of profiles for each on the installed WSL distros. This
 //   will first try to read the installed distros from the registry. If that
-//   fails, we'll fall back to the legacy way of launching WSL.exe to read the
-//   distros from the commandline. Reading the registry is slightly more stable
-//   (see GH#7199, GH#9905), but it is certainly BODGY
+//   fails, we'll assume there are no WSL distributions installed.
+//   Reading the registry is slightly more stable (see GH#7199, GH#9905),
+//   but it is certainly BODGY
 // Arguments:
 // - <none>
 // Return Value:
@@ -333,6 +232,4 @@ void WslDistroGenerator::GenerateProfiles(std::vector<winrt::com_ptr<implementat
             }
         }
     }
-
-    legacyGenerate(profiles);
 }

src/features.xml

@@ -117,18 +117,6 @@
         </alwaysDisabledBrandingTokens>
     </feature>
 
-    <feature>
-        <name>Feature_DECPSViaMidiPlayer</name>
-        <description>Enables playing sound via DECPS using the MIDI player.</description>
-        <stage>AlwaysDisabled</stage>
-        <!-- We're disabling this for WindowsInbox and Stable because it requires an additional
-             package dependency or library dependency. -->
-        <alwaysEnabledBrandingTokens>
-            <brandingToken>Dev</brandingToken>
-            <brandingToken>Preview</brandingToken>
-        </alwaysEnabledBrandingTokens>
-    </feature>
-
     <feature>
         <name>Feature_ScrollbarMarks</name>
         <description>Enables the experimental scrollbar marks feature.</description>

src/host/alias.cpp

@@ -817,18 +817,6 @@ void Alias::s_ClearCmdExeAliases()
     CATCH_RETURN();
 }
 
-// Routine Description:
-// - Trims leading spaces off of a string
-// Arguments:
-// - str - String to trim
-void Alias::s_TrimLeadingSpaces(std::wstring& str)
-{
-    // Erase from the beginning of the string up until the first
-    // character found that is not a space.
-    str.erase(str.begin(),
-              std::find_if(str.begin(), str.end(), [](wchar_t ch) { return !std::iswspace(ch); }));
-}
-
 // Routine Description:
 // - Trims trailing \r\n off of a string
 // Arguments:
@@ -1148,9 +1136,6 @@ std::wstring Alias::s_MatchAndCopyAlias(const std::wstring& sourceText,
     // Trim trailing \r\n off of sourceCopy if it has one.
     s_TrimTrailingCrLf(sourceCopy);
 
-    // Trim leading spaces off of sourceCopy if it has any.
-    s_TrimLeadingSpaces(sourceCopy);
-
     // Check if we have an EXE in the list that matches the request first.
     auto exeIter = g_aliasData.find(exeName);
     if (exeIter == g_aliasData.end())

src/host/alias.h

@@ -29,7 +29,6 @@ public:
                                             size_t& lineCount);
 
 private:
-    static void s_TrimLeadingSpaces(std::wstring& str);
     static void s_TrimTrailingCrLf(std::wstring& str);
     static std::deque<std::wstring> s_Tokenize(const std::wstring& str);
     static std::wstring s_GetArgString(const std::wstring& str);

src/host/consoleInformation.cpp

@@ -382,7 +382,8 @@ MidiAudio& CONSOLE_INFORMATION::GetMidiAudio()
 {
     if (!_midiAudio)
     {
-        _midiAudio = std::make_unique<MidiAudio>();
+        const auto windowHandle = ServiceLocator::LocateConsoleWindow()->GetWindowHandle();
+        _midiAudio = std::make_unique<MidiAudio>(windowHandle);
         _midiAudio->Initialize();
     }
     return *_midiAudio;

src/host/ut_host/AliasTests.cpp

@@ -340,10 +340,10 @@ class AliasTests
         auto rgwchTargetBefore = std::make_unique<wchar_t[]>(cchTarget);
         wcscpy_s(rgwchTargetBefore.get(), cchTarget, rgwchTarget.get());
         size_t cbTargetUsed = 0;
-        const auto cbTargetUsedExpected = cbTarget;
+        const auto cbTargetUsedBefore = cbTargetUsed;
 
         DWORD dwLines = 0;
-        const auto dwLinesExpected = dwLines + 1;
+        const auto dwLinesBefore = dwLines;
 
         // Register the correct alias name before we try.
         std::wstring exe(L"exe.exe");
@@ -351,9 +351,7 @@ class AliasTests
         std::wstring target(L"someTarget");
         Alias::s_TestAddAlias(exe, source, target);
 
-        auto targetExpected = target + L"\r\n";
-
-        // We should be able to match through the leading spaces. They should be stripped.
+        // Leading spaces should bypass the alias. This should not match anything.
         Alias::s_MatchAndCopyAliasLegacy(pwszSource,
                                          cbSource,
                                          rgwchTarget.get(),
@@ -362,9 +360,9 @@ class AliasTests
                                          exe,
                                          dwLines);
 
-        VERIFY_ARE_EQUAL(cbTargetUsedExpected, cbTargetUsed, L"No target bytes should be used.");
-        VERIFY_ARE_EQUAL(String(targetExpected.data(), gsl::narrow<int>(targetExpected.size())), String(rgwchTarget.get(), cchTarget), L"Target string should match expected.");
-        VERIFY_ARE_EQUAL(dwLinesExpected, dwLines, L"Line count be updated to 1.");
+        VERIFY_ARE_EQUAL(cbTargetUsedBefore, cbTargetUsed, L"No bytes should be used if nothing was found.");
+        VERIFY_ARE_EQUAL(String(rgwchTargetBefore.get(), cchTarget), String(rgwchTarget.get(), cchTarget), L"Target string should be unmodified.");
+        VERIFY_ARE_EQUAL(dwLinesBefore, dwLines, L"Line count should pass through.");
     }
 
     TEST_METHOD(TrimTrailing)