[mutter] clutter/actor: Queue redraw on no-layout parents when unmapping

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

commit c88615aac869bf94a0e9ebc372396eabc640c0a3
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Sun Nov 1 12:33:59 2020 +0100

    clutter/actor: Queue redraw on no-layout parents when unmapping
    
    As explained in https://gitlab.gnome.org/GNOME/mutter/-/issues/1494,
    with commit 29caa5bea576ed056aa6c82de192426abe6019ae we stopped queueing
    a relayout for the parent of the removed actor in
    clutter_actor_remove_child_internal(). This relayout was, as opposed to
    the relayout in clutter_actor_real_hide()/clutter_actor_real_unmap(),
    queued unconditionally without looking at the parents NO_LAYOUT flag.
    
    Now while that relayout in clutter_actor_remove_child_internal() would
    do unnecessary work if the parent had the NO_LAYOUT flag set, it did
    also queue a redraw of the parent, which is necessary in any case.
    
    So by removing that relayout in clutter_actor_remove_child_internal(),
    we stopped queueing redraws for NO_LAYOUT parents when a child gets
    removed from the scenegraph. This caused bugs where the texture of the
    child would be left visible on the screen even though the child got
    destroyed.
    
    To fix this, make sure again that we always queue a redraw on the parent
    when unmapping a child.
    
    Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1494

 clutter/clutter/clutter-actor.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)
---
diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index e1ff406b0a..66a0968514 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -1648,9 +1648,13 @@ clutter_actor_real_unmap (ClutterActor *self)
      _clutter_paint_volume_init_static (&priv->last_paint_volume, NULL);
       priv->last_paint_volume_valid = TRUE;
 
-      if (priv->parent && !CLUTTER_ACTOR_IN_DESTRUCTION (priv->parent) &&
-          (!(priv->parent->flags & CLUTTER_ACTOR_NO_LAYOUT)))
-        clutter_actor_queue_relayout (priv->parent);
+      if (priv->parent && !CLUTTER_ACTOR_IN_DESTRUCTION (priv->parent))
+        {
+          if (G_UNLIKELY (priv->parent->flags & CLUTTER_ACTOR_NO_LAYOUT))
+            clutter_actor_queue_redraw (priv->parent);
+          else
+            clutter_actor_queue_relayout (priv->parent);
+        }
     }
 
   /* notify on parent mapped after potentially unmapping