When a present flip operation is still in process during server reset,
the call to present_set_abort_flip may not happen until the screen is
being closed, at which point there is no root window to set pixmaps
for. Check to make sure there's a window before resetting window pixmaps.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
40dc81154a