meta-shaped-texture: Check if the parent has mapped clones as well

When the  WindowActor has mapped clones we should ignore
the unobscured region as well, so we need to walk up and check it
as well.

https://bugzilla.gnome.org/show_bug.cgi?id=725180

src/compositor/meta-shaped-texture.c

@@ -33,6 +33,7 @@
 #include "meta-texture-tower.h"
 
 #include "meta-shaped-texture-private.h"
+#include "meta-window-actor-private.h"
 
 #include <clutter/clutter.h>
 #include <cogl/cogl.h>
@@ -576,8 +577,18 @@ static cairo_region_t *
 effective_unobscured_region (MetaShapedTexture *self)
 {
   MetaShapedTexturePrivate *priv = self->priv;
+  ClutterActor *parent = clutter_actor_get_parent (CLUTTER_ACTOR (self));
 
-  return clutter_actor_has_mapped_clones (CLUTTER_ACTOR (self)) ? NULL : priv->unobscured_region;
+  if (clutter_actor_has_mapped_clones (CLUTTER_ACTOR (self)))
+    return NULL;
+
+  while (parent && !META_IS_WINDOW_ACTOR (parent))
+    parent = clutter_actor_get_parent (parent);
+
+  if (parent && clutter_actor_has_mapped_clones (parent))
+    return NULL;
+
+  return priv->unobscured_region;
 }
 
 gboolean