From 1946ca5954d44d75612857672fc3cf76a49c68b9 Mon Sep 17 00:00:00 2001
From: Jake Dallimore <jake@moodle.com>
Date: Wed, 10 May 2023 09:41:38 +0800
Subject: [PATCH] MDL-76842 auth_lti: don't update the user unless data has
 changed

When receiving data from the LTI launch, or service call, only update
the user record when we know something has changed. This prevents the
creation of many \core\event\user_updated events.
---
 auth/lti/auth.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/auth/lti/auth.php b/auth/lti/auth.php
index dbca92ab8a2..9bf8975868e 100644
--- a/auth/lti/auth.php
+++ b/auth/lti/auth.php
@@ -380,7 +380,11 @@ class auth_plugin_lti extends \auth_plugin_base {
             'lastname' => $userdata['family_name'] ?? $iss,
             'email' => $email
         ];
-        user_update_user($update);
+        $userfieldstocompare = array_intersect_key((array) $user, $update);
+
+        if (!empty(array_diff($update, $userfieldstocompare))) {
+            user_update_user($update); // Only update if there's a change.
+        }
 
         if (!empty($userdata['picture'])) {
             try {