From 8937de6f4029e6353d236bb9a3eefe44ce8195d5 Mon Sep 17 00:00:00 2001
From: Cameron Ball <cameronball@catalyst-au.net>
Date: Wed, 6 Apr 2022 14:42:10 +0800
Subject: [PATCH] MDL-74438 cache: Check if cached value is boolean false

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

diff --git a/cache/stores/file/lib.php b/cache/stores/file/lib.php
index 514dc9d7b1551..070ab04421ee3 100644
--- a/cache/stores/file/lib.php
+++ b/cache/stores/file/lib.php
@@ -518,7 +518,7 @@ protected function prep_data_before_save($data) {
      */
     protected function prep_data_after_read($data) {
         $result = @unserialize($data);
-        if ($result === false) {
+        if ($result === false && $data != serialize(false)) {
             throw new coding_exception('Failed to unserialise data from file. Either failed to read, or failed to write.');
         }
         return $result;