BUG: vid_software_palette 1 causes black screen when moving game window around

[namtsui]

ezQuake version:
3.6.4 on openbsd

OS/device including version:
Specify GPU model, drivers, and the renderer (classic or modern) if graphics-related.
openbsd
6800 xt
vid_renderer 1
gl_renderer AMD Radeon RX 6800 xt (navi21, llvm 13.0)
gl_version 4.6 (compatibility profile) mesa 22.3.7

Describe the bug
The screen becomes black after shuffling windows around.

To Reproduce
Start ezquake using the xmonad tiling window manager and either change tiling layout, shuffle the game window around, or move to a different workspace. The screen becomes black. Changing tiling layout and moving to a different workspace seem to reproduce it on first try compared to shuffling the game window around.

Expected behavior
game window should keep displaying.

Screenshots
If applicable, add screenshots to help explain your problem.
Also please attach your config (.cfg) file

namtsui.cfg.txt

Additional context
I bisected it to this commit d672ab6

The new default for vid_software_palette is 1. Setting vid_software_palette 0 resolved the issue.

[ciscon]

It creates a framebuffer to do the gamma change, if this is causing issues it's almost certainly a compositing/xorg video driver issue/dri issue. I can't speak to the state of any of that in openbsd, but if force disabling dri3 (LIBGL_DRI3_DISABLE=1), switching between the xorg amdgpu and modesettings drivers, or disabling the composite extension entirely in xorg fixes the issue, that's probably it.

[namtsui]

This is reproducible when resizing windows in cwm on openbsd and in xfce on linux.