window-actor/wayland: Remove subsurface actors on dispose

Destroying the window actor also destroys all its children. Subsurfaces
however may get reused. If the client did not unparent them before
the window actor got destroyed, they will be left without actor
which results in a crash.

Unparent all actors of subsurfaces on dispose to avoid that.

Author: Sunderland93

src/compositor/meta-window-actor-wayland.c

@@ -144,10 +144,33 @@ meta_window_actor_wayland_update_regions (MetaWindowActor *actor)
 {
 }
 
+static void
+meta_window_actor_wayland_dispose (GObject *object)
+{
+  MetaWindowActor *window_actor = META_WINDOW_ACTOR (object);
+  MetaSurfaceActor *surface_actor =
+  meta_window_actor_get_surface (window_actor);
+  GList *children;
+  GList *l;
+
+  children = clutter_actor_get_children (CLUTTER_ACTOR (window_actor));
+  for (l = children; l; l = l->next)
+    {
+      ClutterActor *child_actor = l->data;
+
+      if (META_IS_SURFACE_ACTOR_WAYLAND (child_actor) &&
+        child_actor != CLUTTER_ACTOR (surface_actor))
+        clutter_actor_remove_child (CLUTTER_ACTOR (window_actor), child_actor);
+    }
+
+  G_OBJECT_CLASS (meta_window_actor_wayland_parent_class)->dispose (object);
+}
+
 static void
 meta_window_actor_wayland_class_init (MetaWindowActorWaylandClass *klass)
 {
   MetaWindowActorClass *window_actor_class = META_WINDOW_ACTOR_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
   window_actor_class->assign_surface_actor = meta_window_actor_wayland_assign_surface_actor;
   window_actor_class->frame_complete = meta_window_actor_wayland_frame_complete;
@@ -157,6 +180,8 @@ meta_window_actor_wayland_class_init (MetaWindowActorWaylandClass *klass)
   window_actor_class->queue_destroy = meta_window_actor_wayland_queue_destroy;
   window_actor_class->set_frozen = meta_window_actor_wayland_set_frozen;
   window_actor_class->update_regions = meta_window_actor_wayland_update_regions;
+
+  object_class->dispose = meta_window_actor_wayland_dispose;
 }
 
 static void

src/wayland/meta-wayland-subsurface.c

@@ -292,7 +292,8 @@ unparent_actor (MetaWaylandSurface *surface)
     return;
 
   parent_actor = clutter_actor_get_parent (actor);
-  clutter_actor_remove_child (parent_actor, actor);
+  if (parent_actor)
+    clutter_actor_remove_child (parent_actor, actor);
 }
 
 static void
@@ -490,6 +491,7 @@ surface_handle_parent_surface_destroyed (struct wl_listener *listener,
                                                  surface,
                                                  sub.parent_destroy_listener);
 
+  g_node_unlink (surface->subsurface_branch_node);
   surface->sub.parent = NULL;
 }
 

src/wayland/meta-wayland-surface.c

@@ -1328,13 +1328,6 @@ meta_wayland_surface_notify_unmapped (MetaWaylandSurface *surface)
   g_signal_emit (surface, surface_signals[SURFACE_UNMAPPED], 0);
 }
 
-static void
-unlink_note (GNode    *node,
-             gpointer  data)
-{
-  g_node_unlink (node);
-}
-
 static void
 wl_surface_destructor (struct wl_resource *resource)
 {
@@ -1383,14 +1376,7 @@ wl_surface_destructor (struct wl_resource *resource)
   if (surface->wl_subsurface)
     wl_resource_destroy (surface->wl_subsurface);
 
-  if (surface->subsurface_branch_node)
-    {
-      g_node_children_foreach (surface->subsurface_branch_node,
-                               G_TRAVERSE_NON_LEAVES,
-                               unlink_note,
-                               NULL);
-      g_clear_pointer (&surface->subsurface_branch_node, g_node_destroy);
-    }
+  g_clear_pointer (&surface->subsurface_branch_node, g_node_destroy);
 
   g_hash_table_destroy (surface->shortcut_inhibited_seats);