The root window, and by extension any damage records referencing it,
may be destroyed before shared pixmaps referencing it, which resulted in
use-after-free / double-free in PixmapStopDirtyTracking.
Fixes: b5b292896f ("prime: Sync shared pixmap from root window instead of screen pixmap")
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>