[gtk+/gtk-3-22] notebook: Don't leak arrow gadgets

[Matthias Clasen <matthiasc src gnome org>]

commit 7d695068e2634e7dcc2aa9943ed577b806cb0af7
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Nov 23 14:44:37 2016 -0500

    notebook: Don't leak arrow gadgets
    
    This was pointed out in
    https://bugzilla.gnome.org/show_bug.cgi?id=774743

 gtk/gtknotebook.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index ce08875..cc0cae0 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -1843,6 +1843,10 @@ gtk_notebook_finalize (GObject *object)
   g_clear_object (&priv->gadget);
   g_clear_object (&priv->header_gadget);
   g_clear_object (&priv->tabs_gadget);
+  g_clear_object (&priv->arrow_gadget[0]);
+  g_clear_object (&priv->arrow_gadget[1]);
+  g_clear_object (&priv->arrow_gadget[2]);
+  g_clear_object (&priv->arrow_gadget[3]);
   g_clear_object (&priv->stack_gadget);
 
   G_OBJECT_CLASS (gtk_notebook_parent_class)->finalize (object);