Snapping and exiting fullscreen firefox without titlebar (and CSD apps) is broken

Submitted by Aleks

Assigned to Olivier Fourdan @olivier

Link to original bug (#14807)

Description

1. Since firefox version 60 or so it is possible to disable the titlebar. However, snapping the maximized firefox-window to the side leaves gaps around the window and works only properly at the second time. Reproduce: Maximize firefox without titlebar. Drag firefox to the side to snap it.

2. Also leaving the firefox fullscreen-mode leaves gaps around the window. Reproduce: Make firefox without titlebar fullscreen by pressing F11. Press F11 again to leave fullscreen.

Version: 4.13.0