[mutter/gnome-3-10] window-actor: Guard against %NULL frame mask

[Florian Müllner <fmuellner src gnome org>]

commit 7943cf50d480e5841cf7012557ac094f4c5489c5
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Jan 10 06:26:57 2014 -0500

    window-actor: Guard against %NULL frame mask
    
    Creating a new cogl texture may fail, in which case the intent to
    free it will crash. While something is clearly wrong (insanely
    large window, oom, ...), crashing the WM is harsh and we should
    try to avoid it if at all possible, so carry on.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=722266

 src/compositor/meta-window-actor.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/compositor/meta-window-actor.c b/src/compositor/meta-window-actor.c
index 12ff76c..ed19647 100644
--- a/src/compositor/meta-window-actor.c
+++ b/src/compositor/meta-window-actor.c
@@ -2229,7 +2229,8 @@ build_and_scan_frame_mask (MetaWindowActor       *self,
 
   meta_shaped_texture_set_mask_texture (META_SHAPED_TEXTURE (priv->actor),
                                         mask_texture);
-  cogl_object_unref (mask_texture);
+  if (mask_texture)
+    cogl_object_unref (mask_texture);
 
   g_free (mask_data);
 }