From 57aed80df6d62142b62e903669875de7fd830dfe Mon Sep 17 00:00:00 2001
From: Brendan Heywood <brendan@catalyst-au.net>
Date: Mon, 12 Oct 2020 15:59:31 +1100
Subject: [PATCH] MDL-68983 cache: Fix bug with readonly session combined with
 lock debug

---
 lib/classes/session/manager.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/classes/session/manager.php b/lib/classes/session/manager.php
index c3b0baa6194d1..8934080a8604f 100644
--- a/lib/classes/session/manager.php
+++ b/lib/classes/session/manager.php
@@ -1274,6 +1274,10 @@ public static function update_recent_session_locks($sessionlock) {
             return;
         }
 
+        if (defined('READ_ONLY_SESSION') && READ_ONLY_SESSION && !empty($CFG->enable_read_only_sessions)) {
+            return;
+        }
+
         $SESSION->recentsessionlocks = self::get_recent_session_locks();
         array_push($SESSION->recentsessionlocks, $sessionlock);