Index: includes/menu.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/menu.inc,v
retrieving revision 1.378
diff -u -p -r1.378 menu.inc
--- includes/menu.inc	30 Jan 2010 03:38:22 -0000	1.378
+++ includes/menu.inc	8 Feb 2010 11:19:37 -0000
@@ -3206,8 +3206,10 @@ function _menu_router_build($callbacks) 
 
     // Calculate out the file to be included for each callback, if any.
     if ($item['file']) {
-      $file_path = $item['file path'] ? $item['file path'] : drupal_get_path('module', $item['module']);
-      $item['include file'] = $file_path . '/' . $item['file'];
+      if (empty($item['file path'])) {
+        $item['file path'] = drupal_get_path('module', $item['module']);
+      }
+      $item['include file'] = $item['file path'] . '/' . $item['file'];
     }
   }