From f5c263836db4b9ff14afa5fb110420b5da2f5218 Mon Sep 17 00:00:00 2001
From: Ankit Agarwal <ankit@moodle.com>
Date: Tue, 3 Sep 2013 13:36:08 +0800
Subject: [PATCH] MDL-41558 cache: Identifiers should never be passed as null
 to cache::make()

---
 cache/classes/definition.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cache/classes/definition.php b/cache/classes/definition.php
index 1b19fb2f2ed..da5cd4cc209 100644
--- a/cache/classes/definition.php
+++ b/cache/classes/definition.php
@@ -756,7 +756,7 @@ class cache_definition {
      */
     public function set_identifiers(array $identifiers = array()) {
         foreach ($this->requireidentifiers as $identifier) {
-            if (!array_key_exists($identifier, $identifiers)) {
+            if (!isset($identifiers[$identifier])) {
                 throw new coding_exception('Identifier required for cache has not been provided: '.$identifier);
             }
         }