Terminal adding a space between characters

[dmmartins]

OS/Web Information

• Web Browser: Chrome Version 93.0.4577.82 (Official Build) (x86_64)
• Local OS: macOS 10.15.7
• Remote OS: Linux 4.19.0-16-cloud-amd64 Debian 4.19.181-1
• Remote Architecture: amd64
• code-server --version: 3.12.0 b37ff28

Steps to Reproduce

Couldn't find a way to reproduce yet, but it's happening at least once a day. After a terminal is open for a while, the terminal looks like the screenshot attached

Expected

Actual

Logs

Screenshot

Normal terminal

After some time (a few hours)

Notes

This issue can be reproduced in VS Code: No

Also this didn't happen on previous versions. Started happening after I upgraded to 3.12.0

[jsjoeio]

Oh wow...I wonder if that's font rendering issue or something?

Are you using a custom font?

[dmmartins]

No, default chrome fonts. It didn't happen again since I open the ticket, I'll check if there's actually a space char there or is just rendering when it happens again.

[jsjoeio]

No, default chrome fonts.

Sorry, I meant have you specified a font or changed anything related to fonts in settings.json inside code-server?

It didn't happen again since I open the ticket

Well, that's good! Okay, I'll let you close this then after checking again.

[dmmartins]

I meant have you specified a font or changed anything related to fonts in settings.json inside code-server?

default font as well.

I found a way to reproduce it:

1. open the editor and open a terminal
2. reload the page

resizing the page will fix it

[jsjoeio]

I found a way to reproduce it:

Hmm...I'm on macOS + Brave and followed those instructions. I can't reproduce though.

Screen.Recording.2021-09-22.at.10.01.18.AM.mov

Tried Chrome as well. No luck. I wonder if it's a browser setting?

Screen.Recording.2021-09-22.at.10.03.13.AM.mov

[rednaks]

I think this bug was reported several times and it really needs to be investigated. The workaround is the set the font in the config and don't keep it empty : #3848 (comment)

[jsjoeio]

@rednaks unfortunately we can't investigate if we can't reproduce this issue.

In the past, it's usually custom font or browser-related. If you can provide specific instructions for reproducing in code-server, I'm happy to take a look!

Otherwise, it could be an issue with the browser, custom font, or xterm.js

[rednaks]

@jsjoeio well that's interesting, I just opened xterm,js on my browser and got the same issue, I'm using firefox. on chromium it looks good. How can I investigate this further ?

[jsjoeio]

Wow! Thanks for sharing @rednaks! Indeed, this looks to be an issue with xterm then.

How can I investigate this further

Great question! If I were you, I'd open an issue under their repo and see what they say. I took a brief look and didn't see anything already open (but I'd double-check).

[jsjoeio]

And if you don't mind @rednaks, can you link it here? Then I can mark this upstream and close

[bpmct]

It’s possible this has something to do with your host operating system’s locale and encoding, which makes it run weirdly in VS Code?

I have also seen terminal sessions in code-server have this issue, but haven’t been able to reproduce consistently.

[senyai]

I just saw this in desktop VS Code 1.61.2