Unexpected ESC[K over ssh

[BLink7R]

Windows Terminal version

1.25.1241.0

Windows build number

10.0.22631.0

Other Software

OpenSSH_for_Windows_10.0p2 Win32-OpenSSH-GitHub, LibreSSL 4.2.0
PowerShell 7.6.1

Steps to reproduce

1. pwsh script, save as test.ps1 at $home

$w = $Host.UI.RawUI.WindowSize.Width
"$([char]27)[3;1Ha$(' ' * ($w - 1))$([char]27)[Kb"
cat "$home/test.ps1" | echo

2. ssh

 ssh user@ip -t pwsh ./test.ps1

3. Modify the script:

$w = $Host.UI.RawUI.WindowSize.Width
"$([char]27)[3;1Ha$(' ' * ($w - 1))$([char]27)[Kb"

4. ssh again

Expected Behavior

step 1 and 2: the character b should appear in the second line

step 3 and 4: the character b shoud appear at the end of the first line

（output the script content just to make sure that i didn't mix it up）

Actual Behavior

step 2: the character b appears at the end of the first line

Use

 ssh user@ip -t pwsh ./test.ps1 | sed 's/\x1b/\\e/g'

to show the escape sequence, result is :

We can see that there is an extra ESC[K

step 4: after I add the ESC[K to script, things get reversed

the escape sequence is:

[BLink7R]

This issue appears to be a bug in the older version of conhost.exe. I compiled OpenSSH from source and modified it to use openconsole.exe instead of the system conhost.exe for the ConPTY backend, which resolved the problem.

[DHowett]

Thank you for testing that out. We have a bit of a triage backlog (and I'm sorry to have let this sit!)