GtkGraphicsOffload:black-background makes video output black when behind toplevel with GSK_RENDERER=gl
A small regression from !7147 (merged):
- run
GSK_RENDERER=gl gtk4-demo --run=video_player
- play hw-accelerated video
Observed behavior: the video area is black as long as video controls are visible. Once they are hidden and the subsurface is in the front, things are displayed correctly.
My off-hand suspicion is that the fix from !7053 (merged) needs another adoption.