[gtk+] Plug a leak

[Matthias Clasen <matthiasc src gnome org>]

commit 4dc47c37145509d63482f11a39ec0bab559421c1
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Sep 6 19:16:43 2015 -0400

    Plug a leak
    
    A type class reference gotten with g_type_class_ref must be released
    with g_type_class_unref, or else we leak.

 gtk/gtkcsswidgetnode.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkcsswidgetnode.c b/gtk/gtkcsswidgetnode.c
index 4e67b51..f579c12 100644
--- a/gtk/gtkcsswidgetnode.c
+++ b/gtk/gtkcsswidgetnode.c
@@ -145,6 +145,7 @@ static gboolean
 widget_needs_widget_path (GtkWidget *widget)
 {
   static GetPathForChildFunc funcs[2];
+  GtkContainerClass *class;
   GtkWidget *parent;
   GetPathForChildFunc parent_func;
   guint i;
@@ -152,8 +153,14 @@ widget_needs_widget_path (GtkWidget *widget)
   if (G_UNLIKELY (funcs[0] == NULL))
     {
       i = 0;
-      funcs[i++] = GTK_CONTAINER_CLASS (g_type_class_ref (GTK_TYPE_CONTAINER))->get_path_for_child;
-      funcs[i++] = GTK_CONTAINER_CLASS (g_type_class_ref (GTK_TYPE_BOX))->get_path_for_child;
+
+      class = (GtkContainerClass*)g_type_class_ref (GTK_TYPE_CONTAINER);
+      funcs[i++] = class->get_path_for_child;
+      g_type_class_unref (class);
+
+      class = (GtkContainerClass*)g_type_class_ref (GTK_TYPE_BOX);
+      funcs[i++] = class->get_path_for_child;
+      g_type_class_unref (class);
 
       g_assert (i == G_N_ELEMENTS (funcs));
     }