Crashing application will cause 'ghost window'

[AdaShoelace]

In the event of a crashing application the window manager is not notified of the unmapping of the window and can therefor not delete the corresponding WindowWrapper.

This in turn leads to 'ghost windows' that can not be interacted with hence can not be deleted manually.
These ghost windows will cause the different layouts to behave as if they are still there, formatting existing windows in an unintended way and allocating screen space just to waste it.

[AdaShoelace]

Reopening this issue due to reappearance of the bug.
It seems that some applications close top level windows (or hide) without sending an iccm-message telling us that the window is disappearing. This in term inhibits the clean-up of the corresponding WindowWrapper and gives faulty behaviour in tiling layouts. Desktop area containing no window will be allocated with no possibility to reclaim it.

In order to fix: identify under what circumstances this happens.
Can be reproduced with kazam.