Thinking back, the event that possibly made this bug disappear could have been...:
While reading how to submit a bug, I discovered there's a system monitor app (I had always used top from the command line).
The first time I resized the system monitor window vertically, it resized itself glacially slowly back to the size it started at. I don't recall any other window than the File Chooser doing this before. When I tried to resize the system monitor window a second time, it stayed where I put it. Since then, the bug seems to have disappeared.
Thinking back, the event that possibly made this bug disappear could have been...:
While reading how to submit a bug, I discovered there's a system monitor app (I had always used top from the command line).
The first time I resized the system monitor window vertically, it resized itself glacially slowly back to the size it started at. I don't recall any other window than the File Chooser doing this before. When I tried to resize the system monitor window a second time, it stayed where I put it. Since then, the bug seems to have disappeared.