[gtk+] csswidgetnode: Always return a valid style

[Benjamin Otte <otte src gnome org>]

commit 6f9969f4fe112006a9316575d3beeea4a4ed6c60
Author: Benjamin Otte <otte redhat com>
Date:   Fri Feb 13 22:04:26 2015 +0100

    csswidgetnode: Always return a valid style

 gtk/gtkcsswidgetnode.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkcsswidgetnode.c b/gtk/gtkcsswidgetnode.c
index d142c93..eb640ea 100644
--- a/gtk/gtkcsswidgetnode.c
+++ b/gtk/gtkcsswidgetnode.c
@@ -38,6 +38,9 @@ gtk_css_widget_node_update_style (GtkCssNode   *cssnode,
                                   GtkCssChange  pending_change,
                                   GtkCssStyle  *old_style)
 {
+  if (old_style == NULL)
+    return GTK_CSS_NODE_CLASS (gtk_css_widget_node_parent_class)->update_style (cssnode, pending_change, 
old_style);
+
   return NULL;
 }