No menu_rebuild recurse

menu-no-rebuild-recurse.patch

diff --git a/includes/menu.inc b/includes/menu.inc
index ab97722..7181768 100644
--- a/includes/menu.inc
+++ b/includes/menu.inc
@@ -2767,7 +2767,14 @@ function menu_rebuild() {
       // If we get here and menu_masks was not set, then it is possible a menu
       // is being reloaded, or that the process rebuilding the menu was unable
       // to complete successfully. A missing menu_masks variable could result
-      // in a 404, so re-run the function.
+      // in a 404, so we cannot proceed without completing the rebuild.
+      if (variable_get('menu_rebuild_no_recurse')) {
+        // Sites with long menu_rebuild times or the ability to re-serve stale
+        // pages from external caches may want to fail early, rather than risk
+        // a cache stampede.
+        throw new Exception(t('Menu rebuild still in process or failing'));
+      }
+      // Re-run the function.
       return menu_rebuild();
     }
     return FALSE;