[gtk+] Fix GtkMenuToolButton

[Matthias Clasen <matthiasc src gnome org>]

commit 00e87d24450821f980523b8e8d31064dd3feb131
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Feb 21 21:40:48 2014 -0500

    Fix GtkMenuToolButton
    
    The addition of popovers to menu buttons broke this, by making
    the toolbuttons stay insensitive.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=724799

 gtk/gtkmenubutton.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkmenubutton.c b/gtk/gtkmenubutton.c
index aa11a8d..4664084 100644
--- a/gtk/gtkmenubutton.c
+++ b/gtk/gtkmenubutton.c
@@ -708,6 +708,8 @@ _gtk_menu_button_set_popup_with_func (GtkMenuButton                 *menu_button
       gtk_style_context_add_class (gtk_widget_get_style_context (GTK_WIDGET (menu_button)), "menu-button");
     }
 
+  gtk_widget_set_sensitive (GTK_WIDGET (menu_button), priv->menu != NULL);
+
   g_object_notify (G_OBJECT (menu_button), "popup");
   g_object_notify (G_OBJECT (menu_button), "menu-model");
 }