Index: includes/menu.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/menu.inc,v
retrieving revision 1.268
diff -u -p -r1.268 menu.inc
--- includes/menu.inc	14 Apr 2008 17:48:33 -0000	1.268
+++ includes/menu.inc	22 Apr 2008 02:00:25 -0000
@@ -1257,6 +1257,9 @@ function menu_navigation_links($menu_nam
       $l = $item['link']['localized_options'];
       $l['href'] = $item['link']['href'];
       $l['title'] = $item['link']['title'];
+      if ($item['link']['in_active_trail']) {
+        $l['attributes'] = array('class' => 'active-trail');
+      }
       // Keyed with unique menu id to generate classes from theme_links().
       $links['menu-' . $item['link']['mlid']] = $l;
     }