[clutter] wayland: Check for NULL surface on pointer leave events

[Rob Bradford <rbradford src gnome org>]

commit 29eef6de61157db81a6fac4dca219c0c3f4b8ce8
Author: Rob Bradford <rob linux intel com>
Date:   Tue Sep 3 12:24:20 2013 +0100

    wayland: Check for NULL surface on pointer leave events
    
    In the protocol this is the expected behaviour when the client has
    destroyed the surface.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=707377

 clutter/wayland/clutter-input-device-wayland.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/clutter/wayland/clutter-input-device-wayland.c b/clutter/wayland/clutter-input-device-wayland.c
index 05331d9..60920c9 100644
--- a/clutter/wayland/clutter-input-device-wayland.c
+++ b/clutter/wayland/clutter-input-device-wayland.c
@@ -410,6 +410,9 @@ clutter_wayland_handle_pointer_leave (void *data,
   ClutterStageCogl          *stage_cogl;
   ClutterEvent              *event;
 
+  if (surface == NULL)
+    return;
+
   if (!CLUTTER_IS_STAGE_COGL (wl_surface_get_user_data (surface)))
     return;