be more defensive with the user name

butonic · web-flow · commit dce224b745e7 · 2022-03-11T09:12:04.000+01:00
diff --git a/core/Controller/LoginController.php b/core/Controller/LoginController.php
@@ -143,11 +143,12 @@ public function showLoginForm($user, $redirect_url, $remember_login) {
 			// if the user exists, replace the userid with the username, eg. for LDAP accounts
 			// that have the owncloud internal username set to a uuid.
 			$u = $this->userManager->get($user);
-			if ($u === null) {
-				$parameters['loginName'] = $user;
-			} else {
+			if ($u !== null) {
 				$parameters['loginName'] = $u->getUserName();
 			}
+			if (!\is_string($parameters['loginName']) || $parameters['loginName'] === '') {
+				$parameters['loginName'] = $user;
+			}
 			$parameters['user_autofocus'] = false;
 		} else {
 			$parameters['loginName'] = '';
