#73676 by keve, fix an undefined index.

modules/menu/menu.module

@@ -178,7 +178,7 @@ function menu_form_alter($form_id, &$form) {
     $item = array();
     if ($edit['nid'] > 0) {
       $item = db_fetch_array(db_query("SELECT * FROM {menu} WHERE path = 'node/%d'", $edit['nid']));
-      if (is_array($edit['menu'])) {
+      if (isset($edit['menu']) && is_array($edit['menu'])) {
         $item = !is_array($item) ? $edit['menu'] : (($_POST['op'] == t('Preview')) ? array_merge($item, $edit['menu']) : array_merge($edit['menu'], $item));
       }
     }