From 6d03666d2d17828d7a1908638884fbeec875c3e0 Mon Sep 17 00:00:00 2001
From: Bilal Elmoussaoui <belmouss@redhat.com>
Date: Mon, 11 Mar 2024 11:32:40 +0100
Subject: [PATCH] window/x11: Try harder to find the associated group

Otherwise we would try to create a new group later on which would crash

Fixes #3329

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3656>
---
 src/x11/window-x11.c | 30 +++++++++++++-----------------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index 745c45db1..e57bc8622 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -4549,9 +4549,11 @@ static void
 meta_window_x11_compute_group (MetaWindow *window)
 {
   MetaGroup *group = NULL;
-  MetaWindow *ancestor;
   MetaX11Display *x11_display = window->display->x11_display;
+  MetaWindow *ancestor = meta_window_find_root_ancestor (window);
   Window win_leader = meta_window_x11_get_xgroup_leader (window);
+  Window xwindow = meta_window_x11_get_xwindow (window);
+  Window ancestor_leader = meta_window_x11_get_xgroup_leader (ancestor);
   MetaWindowX11Private *priv =
     meta_window_x11_get_private (META_WINDOW_X11 (window));
 
@@ -4560,21 +4562,19 @@ meta_window_x11_compute_group (MetaWindow *window)
   /* Determine the ancestor of the window; its group setting will override the
    * normal grouping rules; see bug 328211.
    */
-  ancestor = meta_window_find_root_ancestor (window);
 
   if (x11_display->groups_by_leader)
     {
-      if (ancestor != window)
+      if (ancestor != window && ancestor_leader != None)
         group = meta_window_x11_get_group (ancestor);
-      else if (win_leader != None)
+
+      if (win_leader != None && group == NULL)
         group = g_hash_table_lookup (x11_display->groups_by_leader,
                                      &win_leader);
-      else
-        {
-          Window xwindow = meta_window_x11_get_xwindow (window);
-          group = g_hash_table_lookup (x11_display->groups_by_leader,
-                                       &xwindow);
-        }
+
+      if (group == NULL)
+        group = g_hash_table_lookup (x11_display->groups_by_leader,
+                                     &xwindow);
     }
 
   if (group != NULL)
@@ -4584,17 +4584,13 @@ meta_window_x11_compute_group (MetaWindow *window)
     }
   else
     {
-      Window ancestor_leader = meta_window_x11_get_xgroup_leader (ancestor);
 
       if (ancestor != window && ancestor_leader != None)
-        group = meta_group_new (x11_display,
-                                ancestor_leader);
+        group = meta_group_new (x11_display, ancestor_leader);
       else if (win_leader != None)
-        group = meta_group_new (x11_display,
-                                win_leader);
+        group = meta_group_new (x11_display, win_leader);
       else
-        group = meta_group_new (x11_display,
-                                meta_window_x11_get_xwindow (window));
+        group = meta_group_new (x11_display, xwindow);
 
       priv->group = group;
     }