add func. to go through GList backwards.

src/zmapUtils/zmapGLibUtils.c

+/*  File: zmapGLibUtils.c
+ *  Author: Ed Griffiths (edgrif@sanger.ac.uk)
+ *  Copyright (c) Sanger Institute, 2005
+ *-------------------------------------------------------------------
+ * ZMap is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ * or see the on-line version at http://www.gnu.org/copyleft/gpl.txt
+ *-------------------------------------------------------------------
+ * This file is part of the ZMap genome database package
+ * originated by
+ * 	Ed Griffiths (Sanger Institute, UK) edgrif@sanger.ac.uk,
+ *      Roy Storey (Sanger Institute, UK) rds@sanger.ac.uk
+ *
+ * Description: A collection of "add-ons" to GLib that seem useful.
+ *
+ * Exported functions: See ZMap/zmapGLibUtils.h
+ * HISTORY:
+ * Last edited: Oct 13 15:27 2005 (edgrif)
+ * Created: Thu Oct 13 15:22:35 2005 (edgrif)
+ * CVS info:   $Id: zmapGLibUtils.c,v 1.1 2005-11-03 16:14:29 edgrif Exp $
+ *-------------------------------------------------------------------
+ */
+
+#include <ZMap/zmapGLibUtils.h>
+
+
+/* Go through a list in reverse calling the supplied GFunc.
+ * This was lifted from the glib code of g_list. */
+void my_g_list_foreach_reverse(GList *list, GFunc func, gpointer user_data)
+{
+  list = g_list_last(list) ;
+
+  while (list)
+    {
+      GList *prev = list->prev ;
+
+      (*func)(list->data, user_data) ;
+      list = prev ;
+    }
+
+  return ;
+}