Add an expander reftest

This test check that resizing the window when expanding
the expander yields the same end result as having the
expander expanded to begin with. The test uses the inhibit
mechanism introduced in the previous commit.

testsuite/reftests/expand-expander.c

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2014 Red Hat Inc.
+ *
+ * Author:
+ *      Matthias Clasen <mclasen@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gtk/gtk.h>
+
+#include "gtk-reftest.h"
+
+static gboolean
+unblock (gpointer data)
+{
+  reftest_uninhibit_snapshot ();
+  return G_SOURCE_REMOVE;
+}
+
+G_MODULE_EXPORT void
+expand_expander (GtkWidget *widget)
+{
+  reftest_inhibit_snapshot ();
+  gtk_expander_set_expanded (GTK_EXPANDER (widget), TRUE);
+  g_timeout_add (500, unblock, NULL);
+}