If a modal window is closed, usually, it will go behind its parent. The
reason for this is that Workspace::constrainedStackingOrder() puts only
AbstractClient transients above parents, not Deleted transients.
So, if fade/glide/scale effect animates the disappearing of a transient,
unfortunately, one can't see that animation.
== Demos
=== Closing of a transient and parent window
Before:
https://www.youtube.com/watch?v=XiLq7EAVCp0
After:
https://www.youtube.com/watch?v=cH_Ki-sqY8M
=== Scale effect
Before:
https://www.youtube.com/watch?v=Eb2a3U7R10I
After:
https://www.youtube.com/watch?v=4AKu3fdrnYQ
=== Sheet effect
Before:
https://www.youtube.com/watch?v=xPPSnR5FUU0
After:
https://www.youtube.com/watch?v=o_hxTNT-5Hg