use $auth instanceof AuthPlugin instead of not null check

1 files changed, 1 insertions, 1 deletions

diff --git a/feed.php b/feed.php
index 75fabc58d..e76fb0352 100644
--- a/feed.php
+++ b/feed.php
@@ -448,7 +448,7 @@ function rss_buildItems(&$rss, &$data, $opt)
                 $item->authorEmail = $user . '@undisclosed.example.com';
 
                 // get real user name if configured
-                if ($conf['useacl'] && $auth) {
+                if ($conf['useacl'] && $auth instanceof AuthPlugin) {
                     $userInfo = $auth->getUserData($user);
                     if ($userInfo) {
                         switch ($conf['showuseras']) {