Make sure proper user data is available for storages without a owner

Signed-off-by: Julius Härtl <[email protected]>

controller/callbackcontroller.php

@@ -322,6 +322,7 @@ public function emptyfile($doc) {
      * @CORS
      */
     public function track($doc, $users, $key, $status, $url, $token) {
+        \OC_User::setIncognitoMode(true);
 
         list ($hashData, $error) = $this->crypt->ReadHash($doc);
         if ($hashData === NULL) {
@@ -403,6 +404,9 @@ public function track($doc, $users, $key, $status, $url, $token) {
 
                     \OC_Util::tearDownFS();
                     if (!empty($userId)) {
+                        // Set the current user as it is used by the files_version storage to obtain the user
+                        // if no owner has been found e.g. for global external storages
+                        \OC::$server->getUserSession()->setUser($this->userManager->get($ownerId));
                         \OC_Util::setupFS($userId);
                     }