[mutter] clutter/actor: Unref the root node if set as child

[Carlos Garnacho <carlosg src gnome org>]

commit f133de2dd42f4a3f5bf66ef476ce956d2e4931c9
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Mon Nov 4 12:51:43 2019 +0100

    clutter/actor: Unref the root node if set as child
    
    When setting the root node as child of a clip or transform node, we add a
    new reference to it, without removing the one that we've previously added
    when getting it from the actor node (and that won't ever be unset by the
    auto-pointer since the root_node is re-associated).
    
    So, once we add the root node as child and re-define it, unref it.
    
    Fixes https://gitlab.gnome.org/GNOME/mutter/issues/908

 clutter/clutter/clutter-actor.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index af9353e0e..a4214e6a4 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -3934,6 +3934,7 @@ clutter_actor_paint (ClutterActor *self)
       clip_node = clutter_clip_node_new ();
       clutter_paint_node_add_rectangle (clip_node, &clip);
       clutter_paint_node_add_child (clip_node, root_node);
+      clutter_paint_node_unref (root_node);
 
       root_node = g_steal_pointer (&clip_node);
     }
@@ -3947,6 +3948,7 @@ clutter_actor_paint (ClutterActor *self)
 
       transform_node = clutter_transform_node_new (&transform);
       clutter_paint_node_add_child (transform_node, root_node);
+      clutter_paint_node_unref (root_node);
 
       root_node = g_steal_pointer (&transform_node);