diff --git a/ChangeLog b/ChangeLog
index 52cd7261e2..d2beae749c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-05-27 10:33:41  Tim Janik  <timj@imendio.com>
+
+	* gtk/gtkwidget.c: guard gtk_widget_get_snapshot() against
+	invalid or invisible widgets.
+
 2008-05-27  Matthias Clasen  <mclasen@redhat.com>
 
 	Bug 531008 – Crash in gtkprintunixdialog.c
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 171be8525c..7496c00c88 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -8356,6 +8356,10 @@ gtk_widget_get_snapshot (GtkWidget    *widget,
   GdkPixmap *pixmap;
   GList *windows = NULL, *list;
 
+  g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
+  if (!GTK_WIDGET_VISIBLE (widget))
+    return NULL;
+
   /* the widget (and parent_window) must be realized to be drawable */
   if (widget->parent && !GTK_WIDGET_REALIZED (widget->parent))
     gtk_widget_realize (widget->parent);