[gtk+] GtkMenuButton: Don't leak popovers

[Matthias Clasen <matthiasc src gnome org>]

commit fe82dc5fb294c03c2235be0f3105107e89eafbf5
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Dec 17 22:56:30 2014 -0500

    GtkMenuButton: Don't leak popovers
    
    Detach the previous popover from the toplevel when a new one
    is set. This should fix
    
    https://bugzilla.gnome.org/show_bug.cgi?id=741652

 gtk/gtkmenubutton.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkmenubutton.c b/gtk/gtkmenubutton.c
index bc0f437..422c07f 100644
--- a/gtk/gtkmenubutton.c
+++ b/gtk/gtkmenubutton.c
@@ -1167,6 +1167,8 @@ gtk_menu_button_set_popover (GtkMenuButton *menu_button,
       g_signal_handlers_disconnect_by_func (priv->popover,
                                             menu_deactivate_cb,
                                             menu_button);
+
+      gtk_popover_set_relative_to (GTK_POPOVER (priv->popover), NULL);
     }
 
   priv->popover = popover;