Merge branch 'MDL-29318-35' of git://github.com/junpataleta/moodle into MOODLE_35_STABLE

lib/moodlelib.php

@@ -4694,9 +4694,11 @@ function update_internal_user_password($user, $password, $fasthash = false) {
  * @param string $field The user field to be checked for a given value.
  * @param string $value The value to match for $field.
  * @param int $mnethostid
+ * @param bool $throwexception If true, it will throw an exception when there's no record found or when there are multiple records
+ *                              found. Otherwise, it will just return false.
  * @return mixed False, or A {@link $USER} object.
  */
-function get_complete_user_data($field, $value, $mnethostid = null) {
+function get_complete_user_data($field, $value, $mnethostid = null, $throwexception = false) {
     global $CFG, $DB;
 
     if (!$field || !$value) {
@@ -4707,7 +4709,7 @@ function get_complete_user_data($field, $value, $mnethostid = null) {
     $field = core_text::strtolower($field);
 
     // List of case insensitive fields.
-    $caseinsensitivefields = ['username'];
+    $caseinsensitivefields = ['username', 'email'];
 
     // Build the WHERE clause for an SQL query.
     $params = array('fieldval' => $value);
@@ -4734,8 +4736,18 @@ function get_complete_user_data($field, $value, $mnethostid = null) {
     }
 
     // Get all the basic user data.
-    if (! $user = $DB->get_record_select('user', $constraints, $params)) {
-        return false;
+    try {
+        // Make sure that there's only a single record that matches our query.
+        // For example, when fetching by email, multiple records might match the query as there's no guarantee that email addresses
+        // are unique. Therefore we can't reliably tell whether the user profile data that we're fetching is the correct one.
+        $user = $DB->get_record_select('user', $constraints, $params, '*', MUST_EXIST);
+    } catch (dml_exception $exception) {
+        if ($throwexception) {
+            throw $exception;
+        } else {
+            // Return false when no records or multiple records were found.
+            return false;
+        }
     }
 
     // Get various settings and preferences.