The region as passed in is in the source pixmap's coordinate space, so
intersecting it with the clipList (which is in screen space) resulted in
disappointment.
Fixes Firefox popups such as the hamburger menu when using the EGL
backend.
v2:
* Drop vblank->x/y_off from RegionTranslate call, since they're always
0 here (present_wnmd_check_flip rejects flips for x/y_off != 0).
Reported-by: Robert Mader <robert.mader@posteo.de>
Tested-by: Robert Mader <robert.mader@posteo.de>
Reviewed-by: Olivier Fourdan <ofourdan@redhat.com>
Tested-by: Joakim Tjernlund <joakim.tjernlund@infinera.com> # v1
(cherry picked from commit 466b8b43fb355c6040cee45406860b8b8c04e948)
440ed5948b