better exists check for insert mount cache

diff --git a/lib/private/files/config/usermountcache.php b/lib/private/files/config/usermountcache.php
index a2da3e9f528a1f6afd5313792808813406fdee5e..35f4035319019cd5a2017a80b505d62d550509d8 100644 (file)
--- a/lib/private/files/config/usermountcache.php
+++ b/lib/private/files/config/usermountcache.php
@@ -129,7 +129,7 @@ class UserMountCache implements IUserMountCache {
                        'root_id' => $mount->getRootId(),
                        'user_id' => $mount->getUser()->getUID(),
                        'mount_point' => $mount->getMountPoint()
-               ]);
+               ], ['root_id', 'user_id']);
        }
 
        private function setMountPoint(ICachedMountInfo $mount) {