[mutter] window/x11: Don't stop early when trying to find default focus window

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit f5c8e0d96dc952f0e6fb37d91c82d344473c77d4
Author: Sebastian Keller <skeller gnome org>
Date:   Sun Jun 21 00:46:38 2020 +0200

    window/x11: Don't stop early when trying to find default focus window
    
    When trying to find a default focus window, the code iterates through a
    queue of candidates with a timeout between each candidate. If the window
    the current timeout is waiting for gets destroyed, this process just
    stops instead of trying the next window in the queue.
    
    This issue was made more likely to be triggered with the previous change
    to the closed-transient-no-input-parents-queued-default-focus-destroyed
    test due to the introduction of a wait, which can introduce a
    delay between the two destroy commands.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1325

 src/x11/window-x11.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
---
diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index db3fae2f09..ff83615402 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -833,6 +833,18 @@ focus_candidates_maybe_take_and_focus_next (GQueue  **focus_candidates_ptr,
   meta_window_x11_maybe_focus_delayed (focus_window, focus_candidates, timestamp);
 }
 
+static void
+focus_window_delayed_unmanaged (gpointer user_data)
+{
+  MetaWindowX11DelayedFocusData *data = user_data;
+  uint32_t timestamp = data->timestamp;
+
+  focus_candidates_maybe_take_and_focus_next (&data->pending_focus_candidates,
+                                              timestamp);
+
+  meta_window_x11_delayed_focus_data_free (data);
+}
+
 static gboolean
 focus_window_delayed_timeout (gpointer user_data)
 {
@@ -868,7 +880,7 @@ meta_window_x11_maybe_focus_delayed (MetaWindow *window,
 
   data->unmanaged_id =
     g_signal_connect_swapped (window, "unmanaged",
-                              G_CALLBACK (meta_window_x11_delayed_focus_data_free),
+                              G_CALLBACK (focus_window_delayed_unmanaged),
                               data);
 
   data->focused_changed_id =