Merge pull request #9552 from annando/zero-user

Avoid problems with uid=0

diff --combined src/Model/User.php
index ca2878746207efd3248ac8080f2f938fd0aba0ec,76408df8121a87d0fb82791526ffd155459574fc..03ddb4605b8f96d02e38f3b4e9822562dc15c132
--- 1/src/Model/User.php
--- 2/src/Model/User.php
+++ b/src/Model/User.php
@@@ -264,7 -264,7 +264,7 @@@ class Use
         */
        public static function getById($uid, array $fields = [])
        {
-               return DBA::selectFirst('user', $fields, ['uid' => $uid]);
+               return !empty($uid) ? DBA::selectFirst('user', $fields, ['uid' => $uid]) : [];
        }
  
        /**
@@@ -559,7 -559,7 +559,7 @@@
         * @return array
         * @throws HTTPException\NotFoundException
         */
 -      private static function getAuthenticationInfo($user_info)
 +      public static function getAuthenticationInfo($user_info)
        {
                $user = null;