Index: branches/5.2.x/core/units/helpers/user_helper.php
===================================================================
diff -u -N -r16571 -r16748
--- branches/5.2.x/core/units/helpers/user_helper.php	(.../user_helper.php)	(revision 16571)
+++ branches/5.2.x/core/units/helpers/user_helper.php	(.../user_helper.php)	(revision 16748)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: user_helper.php 16571 2017-07-16 18:16:49Z alex $
+* @version	$Id: user_helper.php 16748 2022-11-09 15:41:07Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -339,7 +339,7 @@
 
 			$sql = 'SELECT PortalUserId, Password, PasswordHashingMethod
 					FROM ' . TABLE_PREFIX . 'Users
-					WHERE Email = %1$s OR Username = %1$s';
+					WHERE ' . (strpos($username, '@') === false ? 'Username' : 'Email') . ' = %1$s';
 			$user_info = $this->Conn->GetRow(sprintf($sql, $this->Conn->qstr($username)));
 
 			if ( $user_info ) {