Index: ./includes/theme.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/theme.inc,v
retrieving revision 1.405
diff -u -r1.405 theme.inc
--- ./includes/theme.inc	8 Dec 2007 15:15:25 -0000	1.405
+++ ./includes/theme.inc	19 Dec 2007 05:06:08 -0000
@@ -1084,6 +1084,9 @@
       if (isset($link['href']) && $link['href'] == $_GET['q']) {
         $class .= ' active';
       }
+      else if (!empty($link['in_active_trail'])) {
+        $class .= ' in-active-trail';
+      }
       $output .= '<li class="'. $class .'">';
 
       if (isset($link['href'])) {
Index: ./includes/menu.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/menu.inc,v
retrieving revision 1.232
diff -u -r1.232 menu.inc
--- ./includes/menu.inc	8 Dec 2007 14:06:20 -0000	1.232
+++ ./includes/menu.inc	19 Dec 2007 05:06:10 -0000
@@ -1141,6 +1141,7 @@
       $l = $item['link']['options'];
       $l['href'] = $item['link']['href'];
       $l['title'] = $item['link']['title'];
+      $l['in_active_trail'] = $item['link']['in_active_trail'];
       // Keyed with unique menu id to generate classes from theme_links().
       $links['menu-'. $item['link']['mlid']] = $l;
     }