[metacity] window: Don't refuse to move focus to the grab window

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 23f3656613bc2ffa2e39d1798fe7efdaf68b8e2e
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri May 25 20:18:23 2018 +0200

    window: Don't refuse to move focus to the grab window
    
    We refuse to move focus while a grab operation is in place. While this
    generally makes sense, there's no reason why the window that owns the
    grab shouldn't be given the regular input focus as well - we pretty
    much assume that the grab window is also the focus window anyway.
    
    In fact there's a strong reason for allowing the focus change here:
    If the grab window isn't the focus window, it probably has a modal
    transient that is focused instead, and a likely reason for the focus
    request is that the transient is being unmanaged and we must move
    the focus elsewhere.
    
    https://gitlab.gnome.org/GNOME/mutter/issues/15

 src/core/window.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/core/window.c b/src/core/window.c
index ff2c34a1..3aa5c96f 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -4478,6 +4478,7 @@ meta_window_focus (MetaWindow  *window,
               window->desc, window->input, window->take_focus);
 
   if (window->display->grab_window &&
+      window->display->grab_window != window &&
       window->display->grab_window->all_keys_grabbed &&
       !window->display->grab_window->unmanaging)
     {