Steps to reproduce the issue

We have a multilanguage site (in our case "de-DE" as default and "en-GB" as second language) with restricted areas. When trying to enter a restricted area (en-GB) the Login-Component appears. Login with credentials.

Expected result

After sucessfull login the user should be redirected to the requested page.

Actual result

After sucessfull login the default redirect page (in this case the home page!) is shown. This problem occurs ONLY IN THE ENGLISH VERSION OF THE PAGE.

System information (as much as possible)

PHP 5.4.4
MySQL 5.5.38
Apache 2.0
Joomla! 3.3.3 Stable [ Ember ] 25-July-2014 13:00 GMT

Additional comments

It seems ther is some kind of problem with the BASE64-encoded "return"-string and the $app->getUserState in components/com_users/controllers/user.php.

Line 51: $app->setUserState('users.login.form.return', $data['return']);
here everything seems fine, $data['return'] equals the correct page-url! (something like "/en/?option=com_xy&lang=en&view=xy&Itemid=x")

Line 74: $app->redirect(JRoute::_($app->getUserState('users.login.form.return'), false));
When the UserState is retrieved later, in Line 74, it's value has changed to something generic as "index.php?&Itemid="