Merge "Fix \n handling for HTMLUsersMultiselectField"

diff --cc includes/htmlform/fields/HTMLUsersMultiselectField.php
index 53d1d06,eb88909..286cb8d
--- 1/includes/htmlform/fields/HTMLUsersMultiselectField.php
--- 2/includes/htmlform/fields/HTMLUsersMultiselectField.php
+++ b/includes/htmlform/fields/HTMLUsersMultiselectField.php
@@@ -15,18 -15,16 +15,16 @@@ use MediaWiki\Widget\UsersMultiselectWi
   * @note This widget is not likely to remain functional in non-OOUI forms.
   */
  class HTMLUsersMultiselectField extends HTMLUserTextField {
- 
        public function loadDataFromRequest( $request ) {
-               if ( !$request->getCheck( $this->mName ) ) {
-                       return $this->getDefault();
-               }
+               $value = $request->getText( $this->mName, $this->getDefault() );
  
-               $usersArray = explode( "\n", $request->getText( $this->mName ) );
+               $usersArray = explode( "\n", $value );
                // Remove empty lines
 -              $usersArray = array_values( array_filter( $usersArray, function( $username ) {
 +              $usersArray = array_values( array_filter( $usersArray, function ( $username ) {
                        return trim( $username ) !== '';
                } ) );
-               return $usersArray;
+               // This function is expected to return a string
+               return implode( "\n", $usersArray );
        }
  
        public function validate( $value, $alldata ) {