Important Information

• mpv version 0.34.1(-dirty)
• Distro: Arch Linux
• source of mpv binary: distro package "mpv", package version 1:0.34.1-2
• window manager: bspwm version 0.9.10
• GPU and driver info: Mesa Intel(R) UHD Graphics 600 (GLK 2) (0x3185), mesa version 21.3.5, iris_dri.so

Reproduction steps

• Write a minimal glsl shader (e.g. just returns a constant value - the glsl logic itself does not appear to be the issue) with a //!HOOK block and a //!COMPONENTS option with a value greater than what seems to make sense for the HOOKED texture of that hook point. e.g. for MAIN, MAINPRESUB etc set it to larger than 4, or larger than 1 for LUMA (see attached example) - the latter case can occur when using scripts to generate a shader that (likely incorrectly) assume COMPONENTS == 3 or 4 is always ok due to the return type of the hook() function, but being instructed to hook into a texture for which the number of components that makes sense is less than that value.
• run mpv --no-config --glsl-shader=$the_above_shader.glsl $any_video

Expected behavior

Error with clear explaination that the number of components does not make sense or is too large for the overwritten texture, or a warning that the shader is being ignored and continuing for the same reason.

Actual behavior

mpv aborts and core dumps with the following:
mpv: ../video/out/gpu/video.c:1333: copy_image: Assertion `*offset + count <= 4' failed.

Log file

See attached luma_example.glsl.log for the --log-file output of the luma case example.
Note also stdout/stderr data data as the assert causes mpv to terminate seemingly uncleanly.
I have the output of systemd-coredump but currently no debug symbols available at the time of writing.

Sample files

Example shader linked above in reproduction steps.