[mutter] wayland-surface: Ignore bufferless damage

[Adel Gadllah <agadllah src gnome org>]

commit c8d0a6692163fc6ce23a60b39fc64693a4209b97
Author: Adel Gadllah <adel gadllah gmail com>
Date:   Sun Apr 27 16:18:09 2014 +0200

    wayland-surface: Ignore bufferless damage
    
    Instead of letting a buggy client kill us.

 src/wayland/meta-wayland-surface.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index 3a8a077..3b1935e 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -108,6 +108,10 @@ surface_process_damage (MetaWaylandSurface *surface,
   int i, n_rectangles;
   cairo_rectangle_int_t buffer_rect;
 
+  /* Damage without a buffer makes no sense so ignore that, otherwise we would crash */
+  if (!surface->buffer)
+    return;
+
   buffer_rect.x = 0;
   buffer_rect.y = 0;
   buffer_rect.width = cogl_texture_get_width (surface->buffer->texture);