Terminals render gobbled text in VSCode (browser) on gitpod.io

[geropl]

When using terminals on gitpod.io, sometimes the rendering of terminals is broken, and looks like this:

(Notice the blank areas. Sometimes it shows gobbled characters instead)

When selecting some text in the terminal, it renders correctly though, so the buffer itself seems fine.

This problem is sticky to the tab:

• reload does not help, nor does stop/starting the workspace
• closing the tab, and opening the same (running) workspace in a fresh tab fixes it ✔️

Happy to provide more input, but not sure what would help in this case! 🙏

Potentially related: #3600

Details

• Browser and browser version: Firefox 112.0 (64-bit)
• OS version: Linux Mint 20.3 Cinnamon / 5.4.0-144-generic
• xterm.js version: how to obtain?
• VSCode version: 1.77.3

Steps to reproduce

1. Start some workspaces on gitpod.io, using "VSCode Browser"
2. Repeat until you hit one with broken terminals (seems to be around a 10% chance)

[jerch]

Hmm, this indeed needs more info/testing on your side to get down to the issue behind.

Can you repro this on the xterm.js demo with your system? Problem here is the indirection with gitpod --> vscode in between before getting to xterm.js mechs, which adds complexity and more potential "issue surface".

2. Repeat until you hit one with broken terminals (seems to be around a 10% chance)

Does this only happen for late terminals? Like it is never happening for the early ones? Because there might be a chance that you run into context creation issues by the browser engine for the renderer. With which renderer do see this? If its only webgl, then maybe your engine runs out of gl contexes, if it also happens with the canvas renderer, then maybe there is something wrong with the char atlas.

Maybe related: #4480, #4379

I doubt that this one is related to #3600, as this is mostly because of keyboard issues under android.

[Tyriar]

This could be fixed in gitpod with microsoft/vscode#181359?