Description:
------------
In some cases, the function is called in CLI mode. Although it does not work in CLI mode.

Test script:
---------------
<?php
class IndexController extends Yaf_Controller_Abstract
{
    public function indexAction()
    {
        Yaf_Dispatcher::getInstance()->disableView();

        $a = $b;
        
        $response = new Yaf_Response_HTTP(); 
        var_dump($response->setRedirect('https://yourdomain.com'));
    }
}

Expected result:
----------------
bool(false)

Actual result:
--------------
Notice: Undefined variable: b in /www/application/controllers/Index.php on line 8
Warning: Cannot modify header information - headers already sent by (output started at /www/application/controllers/Index.php:8) in /www/application/controllers/Index.php on line 11
bool(false)