[gtk+] GtkNotebook: Be a bit more safe against cur_page being NULL

[Matthias Clasen <matthiasc src gnome org>]

commit 5127136723f3bc5bbf5cccb5dbca39b894841ee3
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Dec 22 10:52:54 2014 -0500

    GtkNotebook: Be a bit more safe against cur_page being NULL
    
    https://bugzilla.gnome.org/show_bug.cgi?id=477454

 gtk/gtknotebook.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 2635d1c..61ca580 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -3241,7 +3241,6 @@ gtk_notebook_button_release (GtkWidget      *widget,
 {
   GtkNotebook *notebook;
   GtkNotebookPrivate *priv;
-  GtkNotebookPage *page;
 
   if (event->type != GDK_BUTTON_RELEASE)
     return FALSE;
@@ -3249,10 +3248,9 @@ gtk_notebook_button_release (GtkWidget      *widget,
   notebook = GTK_NOTEBOOK (widget);
   priv = notebook->priv;
 
-  page = priv->cur_page;
-
   if (!priv->during_detach &&
-      page->reorderable &&
+      priv->cur_page &&
+      priv->cur_page->reorderable &&
       event->button == priv->pressed_button)
     gtk_notebook_stop_reorder (notebook);