Call to a member function Lang() on a non-object when user is not logged in

[danpospisil]

When user is not logged in, insted of showing him the login form, an error is thrown:
Fatal error: Call to a member function Lang() on a non-object in /var/www/nmvd/tmp/templates_c/FrontEndUsers^53f6817f85fc8b121978a61928d6e31ad0602069.module_db_tpl.FrontEndUsers;feusers_loginform.php on line 43

It's because this is missing (copied from DoAction from FrontEndUsers):
$smarty->assign('feuactionid',$id);
$smarty->assign('feuactionparams',$params);
$smarty->assign('mod',$this);
$smarty->assign($this->GetName(),$this);
but more modifications are needed to make this work.
So instead I modified the code to redirect user to my login form.
$manager = &$gCms->GetHierarchyManager();
$node = &$manager->sureGetNodeByAlias('login');
$content = &$node->GetContent();
if (isset($content) && is_object($content))
{
if ($content->GetURL() != '')
{
redirect($content->GetURL());
}
}

It might help somebody until it's fixed.
Using:
CMSMS 1.11.7
DownloadManager 1.5.3