Ticket #15473: 15473.diff

wp-includes/user.php

@@ -59 +59 @@
         }
 
         wp_set_auth_cookie($user->ID, $credentials['remember'], $secure_cookie);
-        do_action('wp_login', $credentials['user_login']);
+        if ( is_a ($user, 'WP_User') ) {
+                do_action('wp_login', $user->user_login);
+        } else {
+                do_action('wp_login', $credentials['user_login']);
+        }
         return $user;
 }