[gtk+/composite-templates] GtkMenuButton: Override add

[Juan Pablo Ugarte <jpu src gnome org>]

commit 34b900c0d156199c39225d1d82d1f0531e657552
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Aug 24 23:32:41 2012 -0400

    GtkMenuButton: Override add
    
    By removing an existing child in add, if it is our own arrow,
    we can make things work better in GtkBuilder.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=682291

 gtk/gtkmenubutton.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkmenubutton.c b/gtk/gtkmenubutton.c
index c847482..e240fdd 100644
--- a/gtk/gtkmenubutton.c
+++ b/gtk/gtkmenubutton.c
@@ -440,10 +440,26 @@ gtk_menu_button_button_press_event (GtkWidget      *widget,
 }
 
 static void
+gtk_menu_button_add (GtkContainer *container,
+                     GtkWidget    *child)
+{
+  GtkMenuButton *button = GTK_MENU_BUTTON (container);
+
+  if (button->priv->arrow_widget)
+    {
+      gtk_container_remove (container, button->priv->arrow_widget);
+      button->priv->arrow_widget = NULL;
+    }
+
+  GTK_CONTAINER_CLASS (gtk_menu_button_parent_class)->add (container, child);
+}
+
+static void
 gtk_menu_button_class_init (GtkMenuButtonClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
   GtkToggleButtonClass *toggle_button_class = GTK_TOGGLE_BUTTON_CLASS (klass);
 
   g_type_class_add_private (klass, sizeof (GtkMenuButtonPrivate));
@@ -456,6 +472,8 @@ gtk_menu_button_class_init (GtkMenuButtonClass *klass)
   widget_class->state_flags_changed = gtk_menu_button_state_flags_changed;
   widget_class->button_press_event = gtk_menu_button_button_press_event;
 
+  container_class->add = gtk_menu_button_add;
+
   toggle_button_class->toggled = gtk_menu_button_toggled;
 
   /**