[gtk+/gtk-3-22] menu: Don't leak check menu items

[Matthias Clasen <matthiasc src gnome org>]

commit 43b9b7f4e6e1ec2b28eb21fbe4d8d2d29cf11949
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Nov 23 14:50:16 2016 -0500

    menu: Don't leak check menu items
    
    Pointed out in
    https://bugzilla.gnome.org/show_bug.cgi?id=774686

 gtk/gtkmenu.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkmenu.c b/gtk/gtkmenu.c
index 6908a6d..2308040 100644
--- a/gtk/gtkmenu.c
+++ b/gtk/gtkmenu.c
@@ -3745,6 +3745,8 @@ gtk_menu_get_preferred_width (GtkWidget *widget,
       max_toggle_size = indicator_width;
 
       gtk_widget_destroy (menu_item);
+      g_object_ref_sink (menu_item);
+      g_object_unref (menu_item);
     }
 
   min_width += 2 * max_toggle_size + max_accel_width;