SDL on Wayland leaves surface around
Starting and then closing
d2x-rebirth (a SDL2 game) with
SDL_VIDEODRIVER=wayland causes its fullscreen window to be left around in the upper left quarter of the screen. It's drawn on top of everything else, even the lock screen, and stays until the shell exits.
One monitor, 3840x2160 @ 200%,
Closing ScummVM, Xonotic or OpenTyrian in fullscreen mode triggers the same issue.
Closing BZFlag doesn't trigger it, but this game doesn't destroy its Wayland objects on shutdown and just exits immediately.