[gtk+/gtk-3-20] notebook: Update arrow state when switching pages

[Matthias Clasen <matthiasc src gnome org>]

commit 7ebc137190b67b5a648d8f754eec7ee865fc3e1d
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Aug 24 14:10:35 2016 -0400

    notebook: Update arrow state when switching pages
    
    Otherwise, we may end up showing clickable arrows that don't
    do anything.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=770332

 gtk/gtknotebook.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 77a8a8b..ec7a1b0 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -6211,6 +6211,9 @@ gtk_notebook_real_switch_page (GtkNotebook     *notebook,
           gtk_widget_grab_focus (GTK_WIDGET (notebook));
     }
 
+  if (priv->scrollable)
+    gtk_notebook_redraw_arrows (notebook);
+
   gtk_widget_queue_resize (GTK_WIDGET (notebook));
   g_object_notify_by_pspec (G_OBJECT (notebook), properties[PROP_PAGE]);
 }