From 1f20d8dfeda7bd110ba94420a8f9f3b759fb9dda Mon Sep 17 00:00:00 2001
From: Paul Holden <paulh@moodle.com>
Date: Wed, 2 Jun 2021 10:55:40 +0100
Subject: [PATCH] MDL-71835 report_log: correct query returning user fullname
 from DB.

---
 report/log/classes/table_log.php | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/report/log/classes/table_log.php b/report/log/classes/table_log.php
index ec67c4de7ee..53c836072c0 100644
--- a/report/log/classes/table_log.php
+++ b/report/log/classes/table_log.php
@@ -108,31 +108,30 @@ class report_log_table_log extends table_sql {
      * @return string|false
      */
     protected function get_user_fullname($userid) {
-        global $DB;
-
         if (empty($userid)) {
             return false;
         }
 
-        if (!empty($this->userfullnames[$userid])) {
-            return $this->userfullnames[$userid];
+        // Check if we already have this users' fullname.
+        $userfullname = $this->userfullnames[$userid] ?? null;
+        if (!empty($userfullname)) {
+            return $userfullname;
         }
 
         // We already looked for the user and it does not exist.
-        if ($this->userfullnames[$userid] === false) {
+        if ($userfullname === false) {
             return false;
         }
 
         // If we reach that point new users logs have been generated since the last users db query.
-        list($usql, $uparams) = $DB->get_in_or_equal($userid);
         $userfieldsapi = \core_user\fields::for_name();
-        $sql = "SELECT id," . $userfieldsapi->get_sql('', false, '', '', false)->selects .
-                " FROM {user} WHERE id " . $usql;
-        if (!$user = $DB->get_records_sql($sql, $uparams)) {
-            return false;
+        $fields = $userfieldsapi->get_sql('', false, '', '', false)->selects;
+        if ($user = \core_user::get_user($userid, $fields)) {
+            $this->userfullnames[$userid] = fullname($user, has_capability('moodle/site:viewfullnames', $this->get_context()));
+        } else {
+            $this->userfullnames[$userid] = false;
         }
 
-        $this->userfullnames[$userid] = fullname($user, has_capability('moodle/site:viewfullnames', $this->get_context()));
         return $this->userfullnames[$userid];
     }