window dragging breaks the behavior of `--auto-window-resize=yes` option

mpv Information

mpv v0.40.0-390-g67330ba2d Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Oct 11 2025 00:15:31
libplacebo version: v7.357.0 (v7.351.0-85-g63a3d64-dirty)
FFmpeg version: N-121416-g6f1ab828d
FFmpeg library versions:
   libavcodec      62.16.100
   libavdevice     62.2.100
   libavfilter     11.9.100
   libavformat     62.6.101
   libavutil       60.13.100
   libswresample   6.2.100
   libswscale      9.3.100

Other Information

- Windows version: Win10 22H2
- GPU model, driver and version:
- Source of mpv: https://github.com/shinchiro/mpv-winbuild-cmake
- Latest known working version:
- Issue started after the following happened:

Reproduction Steps

• prepare two images with different aspect ratios
• mpv 1.png 2.png --no-config --auto-window-resize=yes --autofit=50%x50% --image-display-duration=3 --log-file=log.txt
• drag window a little bit and do not release the left mouse button
• wait for 2.png to start playing
• release the left mouse button

Expected Behavior

N/A

Actual Behavior

the window reverts to the aspect ratio of 1.png after releasing the left mouse button

https://github.com/user-attachments/assets/eb590457-ba35-4273-9037-3ac6763e2be8

Log File

log.txt

Sample Files

N/A

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.

Reproduce the issue with the provided mpv command, two images with different aspect ratios, and the documented drag sequence; use log.txt while observing the window resize. Trace the handling of window dragging and --auto-window-resize=yes around the transition to 2.png. Done means releasing the mouse no longer restores the aspect ratio of 1.png.