Race(?) on hiding a window leaves the window unresponsive and not hidden

Submitted by Ulrik

Assigned to Olivier Fourdan @olivier

Link to original bug (#13344)

Description

Bug when a window:

1. Is in focus.
2. Receives a focus-out event
3. Hides itself
4. Would get back focus due to the event in (2) if (3) didn't happen.

Steps to reproduce:

1. Run this script, which has two windows W and Y
2. Move Y window to the left
3. Click inside Y to show W again
4. Click inside W and it prints a message from its button-press-event
5. W has focus, now click the Y window's close button
6. W is not hidden and does not respond to click events

GTK version: 3.22

$ xfwm4 --version
	This is xfwm4 version 4.12.3 (revision 7fdcb53) for Xfce 4.12
	Released under the terms of the GNU General Public License.
	Compiled against GTK+-2.24.30, using GTK+-2.24.31.

	Build configuration and supported features:
	- Startup notification support:                 Yes
	- XSync support:                                Yes
	- Render support:                               Yes
	- Xrandr support:                               Yes
	- Embedded compositor:                          Yes
	- KDE systray proxy (deprecated):               No

Attachment 6991, "Python Gtk 3 reproducer":
focusout.py

Version: 4.12.0