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 ) {
Index: branches/5.2.x/core/install/upgrades.sql
===================================================================
diff -u -N -r16645 -r16748
--- branches/5.2.x/core/install/upgrades.sql	(.../upgrades.sql)	(revision 16645)
+++ branches/5.2.x/core/install/upgrades.sql	(.../upgrades.sql)	(revision 16748)
@@ -2956,3 +2956,5 @@
 # ===== v 5.2.2-B3 =====
 INSERT INTO SearchConfig VALUES ('Categories', 'PageContent', 1, 1, 'lu_fielddesc_category_PageContent', 'lc_field_PageContent', 'In-Portal', 'la_text_category', 22, DEFAULT, 1, 'text', 'MULTI:PageRevisions.PageContent', '{ForeignTable}.PageId = {LocalTable}.CategoryId AND {ForeignTable}.RevisionNumber = {LocalTable}.LiveRevisionNumber', NULL, NULL, NULL, NULL, NULL);
 ALTER TABLE Semaphores CHANGE MainIDs MainIDs TEXT NULL;
+
+ALTER TABLE Users ADD KEY Email (Email);
Index: branches/5.2.x/core/install/install_schema.sql
===================================================================
diff -u -N -r16634 -r16748
--- branches/5.2.x/core/install/install_schema.sql	(.../install_schema.sql)	(revision 16634)
+++ branches/5.2.x/core/install/install_schema.sql	(.../install_schema.sql)	(revision 16748)
@@ -323,7 +323,8 @@
   KEY dob (dob),
   KEY IsBanned (IsBanned),
   KEY UserType (UserType),
-  KEY Username (Username)
+  KEY Username (Username),
+  KEY Email (Email)
 );
 
 CREATE TABLE UserCustomData (