Terminal: Some keybindings involving the `Alt`-key are not sent correctly to shell

[dietssa]

Type: Bug

Observed behavior I run a (fish-)shell in the terminal and notice that some keybindings involving the Alt key do not work as expected. I investigated using the command stdbuf -o0 showkey -a to observe the key press events in the terminal:

• Alt + a works as expected.
• Ctrl + Alt + a does not work: No key press registered, expected sequence is ^[^A
  • I checked in the "Keyboard Shortcut" settings that there is no keybinding Ctrl + Alt + a configured.
• Alt + UpArrow does not work correctly: A key press is registered, but the sequence is the same one as for Ctrl + UpArrow: ^[[1;5A instead of expected ^[[1;3A.

Note: The expected sequences are what I see in a Windows Terminal session.

I tried to solve this using the non-default settings in settings.json:

    "terminal.integrated.sendKeybindingsToShell": true,
    "terminal.integrated.allowChords": false,

Without these settings, Alt + UpArrow does not show up as key press at all. The observations above are with these settings.

Desired behavior Keyboard shortcuts involving the Alt key should be correctly forwarded to the shell running in the terminal.

VS Code version: Code 1.98.0 (6609ac3d66f4eade5cf376d1cb76f13985724bcb, 2025-03-04T21:06:18.612Z) OS version: Windows_NT x64 10.0.26100 Modes: Remote OS version: Linux x64 5.15.167.4-microsoft-standard-WSL2

System Info

Item	Value
CPUs	Intel(R) Core(TM) Ultra 7 165H (22 x 3072)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	63.46GB (40.83GB free)
Process Argv	--crash-reporter-id 06cb76c4-f9b1-4fb9-8b22-e2ccc7ffe56f
Screen Reader	no
VM	0%

Item	Value
Remote	WSL: ubuntu
OS	Linux x64 5.15.167.4-microsoft-standard-WSL2
CPUs	Intel(R) Core(TM) Ultra 7 165H (22 x 0)
Memory (System)	31.08GB (29.22GB free)
VM	0%

Extensions (1)

Extension	Author (truncated)	Version
remote-wsl	ms-	0.88.5

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