From 5d8649480857a304c0bee1c36701636ab6b12ced Mon Sep 17 00:00:00 2001
From: Andrew Nicols <andrew@nicols.co.uk>
Date: Wed, 1 Mar 2017 09:18:08 +0800
Subject: [PATCH] MDL-53978 core: Improve cache usage when no callbacks are
 defined

---
 lib/moodlelib.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 8bdfa86a297..2543b87d630 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -7484,8 +7484,9 @@ function get_plugins_with_function($function, $file = 'lib.php', $include = true
     // Including both although I doubt that we will find two functions definitions with the same name.
     // Clearning the filename as cache_helper::hash_key only allows a-zA-Z0-9_.
     $key = $function . '_' . clean_param($file, PARAM_ALPHA);
+    $pluginfunctions = $cache->get($key);
 
-    if ($pluginfunctions = $cache->get($key)) {
+    if ($pluginfunctions !== false) {
 
         // Checking that the files are still available.
         foreach ($pluginfunctions as $plugintype => $plugins) {