The override-redirect window will not be assigned a shell_surface
object. If it is used as a parent window, it will cause a crash
when calling the set_parent function.
The EWMH specification does not describe the behavior of an
override-redirect window as a parent window, so we should ignore
this case.
Signed-off-by: Liu, Kai1 <kai1.liu@intel.com>
(cherry picked from commit b468687dd2663240d1613bf4a917f049ef09af46)
Liu, Kai1
38eb0a96e0