When a window is restored from the notification area, its position is offset by the size of the decoration, to the north-west direction (which corresponds to the WM_NORMAL_HINT gravity setting in my case). Consecutive hiding and restoration cycles cause the window to "travel" until nearly completly leaving the screen or being "blocked" by a panel.
Up until now I've observed the behaviour with two apps:
- Gajim (the roster window)
- Deluge (the main GTK window)
The problem is introduced by commit 62edeb7.
Created attachment 6062
This patch fixes the issue for me.
The patch seems to fix the issue for me too (checked against git master).
Thanks but I already have a patch.
A fix for this has been pushed for both master and xfce-4.12 branches, hopefully without breaking gravity.