[gtk+] Fix a segfault in gdk_window_beep

[Matthias Clasen <matthiasc src gnome org>]

commit 5fdc140dd8f86bdcd25ec6b596b6c92ddfe661ed
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Dec 4 17:25:40 2010 -0500

    Fix a segfault in gdk_window_beep
    
    Not a good idea to cast an instance to a class...

 gdk/gdkwindow.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 4307f34..71959ee 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -8052,7 +8052,7 @@ gdk_window_beep (GdkWindow *window)
 
   if (toplevel)
     {
-      if (GDK_WINDOW_IMPL_CLASS (toplevel)->beep (window))
+      if (GDK_WINDOW_IMPL_GET_CLASS (toplevel->impl)->beep (window))
         return;
     }