From 8f42a13ce79232fa17f1caf2a75fab4947e439af Mon Sep 17 00:00:00 2001
From: Christian Persch <chpe@gnome.org>
Date: Tue, 23 Mar 2010 14:45:07 +0100
Subject: [PATCH] gtknotebook: Fix critical warnings on scroll events

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=604391
---
 gtk/gtknotebook.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 7326673b20..0e1799744b 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -2590,7 +2590,8 @@ gtk_notebook_scroll (GtkWidget      *widget,
   for (i = 0; i < 2; i++)
     {
       if (event_widget == priv->action_widget[i] ||
-          gtk_widget_is_ancestor (event_widget, priv->action_widget[i]))
+          (priv->action_widget[i] &&
+           gtk_widget_is_ancestor (event_widget, priv->action_widget[i])))
         return FALSE;
     }