Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.652
diff -u -p -r1.652 common.inc
--- includes/common.inc	8 Jun 2007 12:51:58 -0000	1.652
+++ includes/common.inc	11 Jun 2007 03:45:58 -0000
@@ -94,6 +94,15 @@ function drupal_get_breadcrumb() {
     $breadcrumb = menu_get_active_breadcrumb();
   }
 
+  // Call highest priority module's hook_breadcrumb
+  $module = end(module_implements('breadcrumb'));
+  if (isset($module)) {
+    $new_breadcrumb = module_invoke($module, 'breadcrumb', $breadcrumb);
+    if (isset($new_breadcrumb) && $new_breadcrumb) {
+      return $new_breadcrumb;
+    }
+  }
+  
   return $breadcrumb;
 }