Incorrect resizing of CLI apps in Teleport Connect on Windows

[ravicious]

Expected behavior:

The top bar in nano takes all available space.

Current behavior:

The top bar in nano is cut off after the last text character.

This was introduced by the update of xterm to 5.1.0 and xterm-addon-fit to 0.7.0 (#20767). For example, in v12 it was added in v12.1.2. v12.1.1 works correctly.

Bug details:

• Teleport version v12+

[gzdunek]

From what I tested, we could improve the behavior by enabling useConpty in nodePty options.
Additionally, we should pass windowsPty options to xterm.js.

I remember that the reason for disabling conpty was issues on windows server/11, but maybe we could enable it by default and add a config option to explicitly disable it, similarly to vscode? https://code.visualstudio.com/docs/terminal/advanced#_windows-and-conpty
Another benefit is that the terminal renders more accurate colors.

windows-conpty.mov

I checked if passing only backend: 'winpty' to xterm.js improves the current situation, but I didn't see much difference.

EDIT: I also looked at the PR that disabled conpty #22971.
Updating node-pty to 1.0.0-beta.6 fixes the error thrown when the shell is closed by closing the tab. Unfortunately, AttachConsole failed error after typing exit is still there.

[ravicious]

The issue with resizing has been addressed by #36568 and which got released in 15.0.0. At the time of creating this issue I didn't check if the master version fixes the problem in any way. I probably forgot that Xterm.js was updated on master.

@gzdunek What do you say about closing this issue and creating another one specifically about enabling conpty on Windows? I can draft the issue later this week. Having a setting for Conpty and Winpty is a good idea, I think.

[gzdunek]

What do you say about closing this issue and creating another one specifically about enabling conpty on Windows? I can draft the issue later this week.

Sounds good, thanks.