Window goes out of screen bounds on misaligned multi-monitor setup

mpv Information

mpv v0.40.0-382-g92aeb6347 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Oct 10 2025 04:13:05
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: 10.0.19045.5440
- GPU model, driver and version: 
- Source of mpv: https://github.com/zhongfly/mpv-winbuild/releases/tag/2025-10-10-92aeb63
- Latest known working version: mpv v0.38.0-743-gad7976c3
- Issue started after the following happened:

Reproduction Steps

I’m using multiple monitors, and the screens are not horizontally aligned (as shown in the image below).
My mpv configuration has border=yes.

The disabled screen 3 doesn’t affect the issue.My screen 1 is positioned slightly higher than screen 2.

Steps to reproduce:

• Maximize the window.

• Enter fullscreen mode.

• Exit fullscreen mode.

At this point, the window goes out of the visible screen area — only the taskbar is visible, while mpv’s window border is positioned outside the screen.

If I align screen 1 and screen 2 horizontally, the issue does not occur.
Also, I tested with versions before around mpv v0.38.0-743-gad7976c3, and the problem didn’t exist even when the screens were not aligned horizontally.

Expected Behavior

The window size is displayed correctly within the screen.

Actual Behavior

The window size exceeds the screen boundaries.

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 maximize, fullscreen, and exit-fullscreen sequence with border=yes on misaligned monitors, using the attached output.txt for context. Compare the window-bounds behavior with versions before and after mpv v0.38.0-743-gad7976c; done means the window remains fully visible after leaving fullscreen in the reported layout.