resizing terminal stretches text somtimes

[joshribakoff-sm]

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Type: Bug

sometimes when resizing some panes have text super large & distorted, other panes do not have the issue.

VS Code version: Code - Insiders 1.71.0-insider (Universal) (b0895f9fcc5b49587a2b187a92bbe6d7efae35fa, 2022-08-08T05:19:27.279Z) OS version: Darwin x64 21.6.0 Modes: Sandboxed: Yes

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz (12 x 2600)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_renderer: enabled_on video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off
Load (avg)	5, 4, 3
Memory (System)	32.00GB (4.36GB free)
Process Argv	--crash-reporter-id 4f6f994d-06c3-4289-b6cd-8f17e07dfe06
Screen Reader	no
VM	0%

Extensions (6)

Extension	Author (truncated)	Version
vscode-eslint	dba	2.2.6
prettier-vscode	esb	9.5.0
vscode-jest-runner	fir	0.4.48
vscode-graphql	Gra	0.7.1
vscode-graphql-syntax	Gra	1.0.4
angular-console	nrw	17.19.1

A/B Experiments

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cppdebug:30492333
pylanb8912:30522163
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c4g48928:30535728
dsvsc012cf:30540253

[joshribakoff-sm]

[LeanderD]

Same problem here (but horizontally) and for me scrolling in the pane with stretched/squashed text doesn't work anymore. I can still move the scrollbar, but nothing happens.

[Tyriar]

This may be fixed with the fix for https://github.com/microsoft/vscode/issues/157444

[meganrogge]

Steps to repro and the error we've been seeing in the console described here https://github.com/microsoft/vscode/issues/158468

[meganrogge]

Don't think it's fixed as I've seen the error in the console in insiders

[Tyriar]

The error from https://github.com/microsoft/vscode/issues/158468

Uncaught TypeError: Cannot read properties of undefined (reading 'ext')
    at e._loadColorsForCell (WebglRenderer.ts:404:95)
    at e._updateModel (WebglRenderer.ts:351:14)
    at e.renderRows (WebglRenderer.ts:298:10)
    at t._renderRows (RenderService.ts:124:20)
    at e._renderCallback (RenderService.ts:64:70)
    at e._innerRefresh (RenderDebouncer.ts:72:10)
    at RenderDebouncer.ts:51:68

Related: https://github.com/microsoft/vscode/issues/157715

[Tyriar]

I wonder if this is related to the resize observer occurring for a previous canvas update but it not firing for the current change when resizes occur in quick succession? https://github.com/xtermjs/xterm.js/blob/c0ef2ccb5a0b2f22f28ed594f3962d75cc83da00/src/browser/renderer/DevicePixelObserver.ts#L9

Example:

• Canvas is changed to to 5x10, resize observer is queued
• Canvas is changed to 10x10, resize observer does not get queued for some reason?
• Resize observer is fired for 5x10 only?

[janosh]

Just stumbled over this in the final 1.71 release. Like @LeanderD said, this also breaks scrolling in terminal.

[gkn]

Consistently gets this error. It seems it occurs when outpout in a bash terminal window is larger than the current window, e.g. I can replicate it by running a "npm outdated" command that has a wide and long output. Window content including characters will then crudely be zoomed in/out when terminal window is resized, and not re-rendered as it used to be before 1.71

Scrolling does not work, and will eventually make the output disappear totally, leaving the terminal window in an unusable state (kill is the only option out)

[fparhat-rbi]

+1 I am able to reproduce this every time and it is quite annoyin

[asdutoit]

Same issue for me:

[dmitri-suvorov-sumup]

Same here on 1.71.0

[Tyriar]

Anyone seeing this could you provide you window.zoomLevel setting and what the output is when you open developer tools (help menu), go to console and run window.devicePixelRatio?

[dmitri-suvorov-sumup]

Anyone seeing this could you provide you window.zoomLevel setting and what the output is when you open developer tools (help menu), go to console and run window.devicePixelRatio?

[gkn]

Zoom level normal, window.devicePixelRatio=1

I also noticed that I keep getting the following error in VS Code Dev tools:

WebglRenderer.ts:404 Uncaught TypeError: Cannot read properties of undefined (reading 'ext') at e._loadColorsForCell (WebglRenderer.ts:404:95) at e._updateModel (WebglRenderer.ts:351:14) at e.renderRows (WebglRenderer.ts:298:10) at t._renderRows (RenderService.ts:124:20) at e._renderCallback (RenderService.ts:64:70) at e._innerRefresh (RenderDebouncer.ts:72:10) at RenderDebouncer.ts:51:68

[Tyriar]

Thanks @gkn and @dmitri-suvorov-sumup, that's useful

[gkn]

A workaround until this bug is fixed, is to disable WebGL in settings, e.g.: "terminal.integrated.gpuAcceleration": "canvas"

[Tyriar]

Looks like all reports are on macOS

[brauliolledo]

Hey @Tyriar, I'm having the same issue on Fedora 36 running on Gnome. I can include more details if needed. The solution posted by @gkn did work for me as a temp workaround.

[Tyriar]

@brauliolledo thanks for letting me know

[Tyriar]

Recording showing the issue: https://github.com/microsoft/vscode/issues/160508#issuecomment-1241796756

[Tyriar]

I've tried and tried, can't reproduce. Will dig into the code and make a defensive change for the thrown exception if I can't find the problem.

[Tyriar]

This is probably where undefined slips in: https://github.com/xtermjs/xterm.js/blob/f9db65c52e4702cf906c14cda1c640342a7b6dca/src/common/buffer/BufferLine.ts#L183-L185

[Tyriar]

Can reproduce 🎉 it's an issue with extended attributes (ie. underline style and color) conflicting with line reflow:

1. Open bash on macOS or Linux
2. Run ls -la to fill viewport
3. Run echo -e '\x1b[4:1masnmdnasdkjlanmlsdkmnalskdmnlaksdmnlaksdmnlaksdlaksdmlkasmdlas\x1b[0m'
4. Reduce the size of the window, errors appear in the console

Repro may be easier in split panes

[Tyriar]

Upstream issue: https://github.com/xtermjs/xterm.js/issues/4108

[gkn]

Seems like @Tyriar has found the issue now but for the record, I get this error on VS Code running on Windows 10 with WSL2 Ubuntu 20.

[danawoodman]

I'm seeing similar behavior to the described issue using the latest VSCode on macOS:

This is new, only occurring in the past few weeks.

[leafac]

Same story here: The issue is happening to me on the latest versions of Visual Studio Code and macOS. It seems like turning off GPU rendering for the terminal works for the time being, while the issue is being fixed…

[kaovilai]

Pretty sure we gotta wait till https://github.com/microsoft/vscode/commit/b24fefc5403ae8152db6d79eb80333f77e199a6f makes it into one of the release tags and an update published.

[airtonix]

Same story here: The issue is happening to me on the latest versions of Visual Studio Code and macOS. It seems like turning off GPU rendering for the terminal works for the time being, while the issue is being fixed…

@leafac what's the setting for that please?

edit:

...
"terminal.integrated.gpuAcceleration": "off"
...