[dmabuf-wayland] Moving window between two screens with different scale resizes it

mpv Information

mpv v0.40.0-55-g3d5949366 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Apr 11 2025 18:25:48
libplacebo version: v7.349.0
FFmpeg version: 7.1.1
FFmpeg library versions:
   libavcodec      61.19.101
   libavdevice     61.3.100
   libavfilter     10.4.100
   libavformat     61.7.100
   libavutil       59.39.100
   libswresample   5.3.100
   libswscale      8.3.100

Other Information

- Linux version: Fedora 41
- Kernel Version: 6.13.9
- GPU Model: Ryzen 7840U
- Mesa/GPU Driver Version: Mesa 25.0.2
- Window Manager and Version: kwin_wayland git master (11.04.25)
- Source of mpv: built from source
- Latest known working version: not sure
- Issue started after the following happened: -

Reproduction Steps

Have two screens, one with scale 100%, the other with scale 160%. Move the window back and forth between the screens.

Expected Behavior

Unless I explicitly resize the window, it stays the same size.

Actual Behavior

The window changes size once it's completely on one or the other screen - so it's not the preferred_scale of the fractional scale v1 protocol that triggers this, but rather mpv acting on the window only being on one output at a time.

Log File

output.txt

Sample Files

No response

I carefully read all instruction and confirm that I did the following:

• I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Start by reproducing the issue in mpv's dmabuf-wayland path with two screens set to 100% and 160% scaling, then inspect output.txt while moving the window between outputs. The change is complete when the window retains its size unless explicitly resized, and the behavior is covered or verified for both outputs.