starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-04 05:35:20 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

ConPTY adds extra newlines symbols at soft-wrapped rows #19599

New Issue
Closed
opened 2026-01-31 06:48:20 +00:00 by claunia · 5 comments
claunia commented 2026-01-31 06:48:20 +00:00
Owner
Copy Link

Originally created by @Mervap on GitHub (Mar 29, 2023).

Windows Terminal version

Not installed

Windows build number

10.0.19045.2788

Other Software

.NET 7.0 x64

Steps to reproduce

  1. Create ConPTY from dotnet (minimized version below, full working code here, based on samples/GUIConsole.ConPTY)
  2. Run powershell.exe
  3. Send 500 'a' charachters to PTY input (as a single row)
  4. Read 500 charachters from PTY output
SafeFileHandle inputRead, inputWrite, outputRead, outputWrite;

CreatePseudoConsole(new COORD { X = 40, Y = 20 }, inputRead, outputWrite, 0, out IntPtr hPC);
ProcessFactory.Start("powershell.exe -nologo", 0x00020016, hPC);

var writer = new StreamWriter(new FileStream(inputWrite, FileAccess.Write)) { AutoFlush = true };
var reader = new StreamReader(new FileStream(outputRead, FileAccess.Read));


// Write long row
writer.Write(new string('a', 500));

// Read output
char[] buf = new char[500];
var bytesRead = reader.ReadBlock(buf, 0, 500);
var output = new string(buf.Take(bytesRead).ToArray());

// Check output
// Expected: zero '\n' characters
// Actual: a lot of '\n' characters
Console.Out.Write(output.Split('\n').Length);

Expected Behavior

Pty output contains zero newlines symbols since only one line was sent

Actual Behavior

PTY adds extra \n to output turning soft-wrapping to hard-wrapping

Originally created by @Mervap on GitHub (Mar 29, 2023). ### Windows Terminal version Not installed ### Windows build number 10.0.19045.2788 ### Other Software .NET 7.0 x64 ### Steps to reproduce 1) Create ConPTY from dotnet (minimized version below, full working code [here](https://github.com/microsoft/terminal/files/11099336/Wrap.zip), based on `samples/GUIConsole.ConPTY`) 2) Run `powershell.exe` 3) Send 500 `'a'` charachters to PTY input (as a single row) 4) Read 500 charachters from PTY output ```c# SafeFileHandle inputRead, inputWrite, outputRead, outputWrite; CreatePseudoConsole(new COORD { X = 40, Y = 20 }, inputRead, outputWrite, 0, out IntPtr hPC); ProcessFactory.Start("powershell.exe -nologo", 0x00020016, hPC); var writer = new StreamWriter(new FileStream(inputWrite, FileAccess.Write)) { AutoFlush = true }; var reader = new StreamReader(new FileStream(outputRead, FileAccess.Read)); // Write long row writer.Write(new string('a', 500)); // Read output char[] buf = new char[500]; var bytesRead = reader.ReadBlock(buf, 0, 500); var output = new string(buf.Take(bytesRead).ToArray()); // Check output // Expected: zero '\n' characters // Actual: a lot of '\n' characters Console.Out.Write(output.Split('\n').Length); ``` ### Expected Behavior Pty output contains **zero** newlines symbols since only one line was sent ### Actual Behavior PTY adds extra `\n` to output turning soft-wrapping to hard-wrapping
claunia added the Resolution-Fix-AvailableArea-OutputIssue-BugProduct-Conpty labels 2026-01-31 06:48:21 +00:00
claunia commented 2026-01-31 06:48:23 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (Mar 29, 2023):

Thanks for the report! I suspect this is fixed in main, but I'm gonna leave this open to validate that either there's already a test for it, or if not, to add one.

If it is fixed in main, then I'm betting it's only fixed in >22000 builds of Windows.

If it's not fixed, well, it should be ☺️

@zadjii-msft commented on GitHub (Mar 29, 2023): Thanks for the report! I suspect this is fixed in `main`, but I'm gonna leave this open to validate that either there's already a test for it, or if not, to add one. If it is fixed in `main`, then I'm betting it's only fixed in >22000 builds of Windows. If it's _not_ fixed, well, it should be ☺️
claunia commented 2026-01-31 06:48:23 +00:00
Author
Owner
Copy Link

@Mervap commented on GitHub (Mar 29, 2023):

Ok, thanks!
Any chance that it would be fixed in win10?

@Mervap commented on GitHub (Mar 29, 2023): Ok, thanks! Any chance that it would be fixed in win10?
claunia commented 2026-01-31 06:48:24 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (Mar 29, 2023):

Probably not, though, our recommendation is going to be using a nuget package to ingest ConPTY. This nuget package doesn't exist yet1 , but when it does, that'll let you use the latest version of ConPTY regardless of what OS version you're on. That's effectively what the Terminal does today (so that we can use ConPTY fixes even on Windows 10). I think there's other folks that have copied what we've done, but that's firmly in the "not yet officially supported" territory.

  1. Originally, this was tracked in #3577, but apparently we have no thread for "productize the conpty nuget" and we should. I'll take a todo item to create one. ↩︎

@zadjii-msft commented on GitHub (Mar 29, 2023): Probably not, though, our recommendation is going to be using a nuget package to ingest ConPTY. This nuget package doesn't exist yet[^1], but when it does, that'll let you use the latest version of ConPTY regardless of what OS version you're on. That's _effectively_ what the Terminal does today (so that we can use ConPTY fixes even on Windows 10). I think there's other folks that have copied what we've done, but that's firmly in the "not yet officially supported" territory. [^1]: Originally, this was tracked in #3577, but apparently we have no thread for "productize the conpty nuget" and _we should_. I'll take a todo item to create one.
claunia commented 2026-01-31 06:48:24 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (Mar 29, 2023):

addenda: now tracking that in #15065

@zadjii-msft commented on GitHub (Mar 29, 2023): addenda: now tracking that in #15065
claunia commented 2026-01-31 06:48:24 +00:00
Author
Owner
Copy Link

@zadjii-msft commented on GitHub (May 5, 2023):

Yep, we definitely already had a test for this one:

10c6206bfe/src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp (L451-L500)

So, I'll just say "fixed in the latest conpty, but that's probably not on Windows 10, so we'll need to start shipping a conpty nuget that folks can consume externally"

@zadjii-msft commented on GitHub (May 5, 2023): Yep, we definitely already had a test for this one: https://github.com/microsoft/terminal/blob/10c6206bfef7d045347327687266832931f47eb6/src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp#L451-L500 So, I'll just say "fixed in the latest conpty, but that's probably not on Windows 10, so we'll need to start shipping a conpty nuget that folks can consume externally"
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
⛺ Reserved
A11yCO
A11yMAS
A11ySev1
A11ySev2
A11ySev3
A11yTTValidated
A11yUsable
A11yVoiceAccess
A11yWCAG
Area-Accessibility
Area-AtlasEngine
Area-AzureShell
Area-Build
Area-Build
Area-Chat
Area-CmdPal
Area-CodeHealth
Area-Commandline
Area-CookedRead
Area-DefApp
Area-Extensibility
Area-Fonts
Area-GroupPolicy
Area-i18n
Area-Input
Area-Interaction
Area-Interop
Area-Localization
Area-Output
Area-Performance
Area-Portable
Area-Quality
Area-Remoting
Area-Rendering
Area-Schema
Area-Server
Area-Settings
Area-SettingsUI
Area-ShellExtension
Area-ShellExtension
Area-ShellExtension
Area-Suggestions
Area-Suggestions
Area-TerminalConnection
Area-TerminalControl
Area-Theming
Area-UserInterface
Area-VT
Area-Windowing
Area-WPFControl
AutoMerge
Blocking-Ingestion
Culprit-Centennial
Culprit-WinUI
Disability-All
Disability-Blind
Disability-LowVision
Disability-Mobility
External-Blocked-WinUI3
Fixed
Gathering-Data
good first issue
HCL-E+D
HCL-WindowsTerminal
Help Wanted
Impact-Compatibility
Impact-Compliance
Impact-Correctness
Impact-Visual
In-PR
InclusionBacklog
InclusionBacklog-Windows TerminalWin32
InclusionCommitted-202206
Issue-Bug
Issue-Docs
Issue-Feature
Issue-Feature
Issue-Question
Issue-Samples
Issue-Scenario
Issue-Task
Needs-Attention
Needs-Author-Feedback
Needs-Bisect
Needs-Discussion
Needs-Repro
Needs-Tag-Fix
Needs-Tag-Fix
Needs-Triage
No-Recent-Activity
Priority-0
Priority-1
Priority-2
Priority-3
Product-Cmd.exe
Product-Colortool
Product-Colortool
Product-Colortool
Product-Conhost
Product-Conpty
Product-Meta
Product-Powershell
Product-Terminal
Product-WSL
pull-request
Mirrored from GitHub Pull Request
 Resolution-Answered
Resolution-By-Design
Resolution-Duplicate
Resolution-External
Resolution-Fix-Available
Resolution-Fix-Committed
Resolution-No-Repro
Resolution-Won't-Fix
Severity-Blocking
Severity-Crash
Severity-DataLoss
spam
this-will-be-a-breaking-change
Tracking-External
WindowsTerminal_Win32
Work-Item
zAskModeBug
zInbox-Bug
No Label Area-Output Issue-Bug Product-Conpty Resolution-Fix-Available
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
claunia
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/terminal#19599
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?