Bug 485712

System: Archlinux
KWin version: 6.0.4

Summary

When playing video in mpv fullscreen, the screen begins to shake after mouse cursor fades.

Steps to Reproduce:

1. Start mpv in wayland (opengl) backend. (--gpu-context=auto point to wayland on my setting)
2. Play any video in fullscreen.
3. Wait for cursor to fade out, and the screen begins to shake until cursor occurs or pause.

Bisect log:
```
# bad: [750fd5e8de7b2be8bd4a4b52df6fc08d2e3fb4cf] Fall back to breeze_cursors if neither configured nor default can be loaded
# good: [166988cef75e6142b72f9bc3f9d58a8cfce1e26e] plugins/screencast: Handle failing to import dmabuf
git bisect start 'HEAD' 'v6.0.3.1'
# bad: [9720ef2e23cf9e2747d493185163f0dfeb36de3e] backends/drm: signal dmabuf feedback if an unsupported modifier is used
git bisect bad 9720ef2e23cf9e2747d493185163f0dfeb36de3e
# good: [fcbeeb0581a0be10f1dbe9b9c6ce3d444f9b4dc4] Unset Window::tile() when the window is closed
git bisect good fcbeeb0581a0be10f1dbe9b9c6ce3d444f9b4dc4
# good: [24e4a9063705d9247967770168a759cdbd304303] backends/drm: don't do direct scanout with buffers that need cropping
git bisect good 24e4a9063705d9247967770168a759cdbd304303
# good: [8b2ddc447e34295fc569897270617a48f979e210] Fix inconsistent default keyboard delay value used in kwin.
git bisect good 8b2ddc447e34295fc569897270617a48f979e210
# bad: [19ffe2ac411b866cd646942d4e3cfb41d8ca89a1] scene/workspacescene: fix direct scanout checks with subsurfaces
git bisect bad 19ffe2ac411b866cd646942d4e3cfb41d8ca89a1
# good: [4919a8f0072a2228000d0e330801f175fb7eb4e3] backends/drm: actually prefer alpha formats again
git bisect good 4919a8f0072a2228000d0e330801f175fb7eb4e3
# first bad commit: [19ffe2ac411b866cd646942d4e3cfb41d8ca89a1] scene/workspacescene: fix direct scanout checks with subsurfaces
```