[Wayland] Window cannot be resized by dragging top* border

mpv Information

mpv v0.41.0-388-g1301fdb2e Copyright © 2000-2026 mpv/MPlayer/mplayer2 projects
 built on Apr  7 2026 19:09:48
libplacebo version: v7.362.0 (v7.360.0-8-g4c654e50)
FFmpeg version: N-123859-ge7696357de
FFmpeg library versions:
   libavcodec      62.29.101
   libavdevice     62.4.100
   libavfilter     11.15.101
   libavformat     62.13.102
   libavutil       60.29.100
   libswresample   6.4.100
   libswscale      9.7.100

Other Information

- Linux version: Arch btw.
- Kernel Version: Yes
- GPU Model: Intel
- Mesa/GPU Driver Version: 26.0.4
- Window Manager and Version: KDE Plasma 6.6.4
- Source of mpv: Yes
- Latest known working version: Unknown
- Issue started after the following happened: Nothing has happened

Reproduction Steps

1. Open video
2. Drag top border

Expected Behavior

Upon mouse pointer release window keeps new window size.

Actual Behavior

Upon mouse pointer release window restores to window size before drag.

Log File

No.

Sample Files

av://lavfi:testsrc=size=600x400

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

• I tested and confirmed that the issue exists with the latest release version or newer.
• 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 resize behavior on Wayland with the provided lavfi test source, then trace the existing window-resize handling in mpv. Done means dragging the top border and releasing the pointer leaves the window at its new size instead of restoring the previous size.