Bug in validate_redirect() function

[Studio384]

In form

<input type="hidden" name="redirect_url" value="index.php" />

I enter my login and password. Login. Redirect.
And Errors:
Notice: Undefined index: host in C:\Program Files\VertrigoServ\www\59\include\functions.php on line 1185
Notice: Undefined index: host in C:\Program Files\VertrigoServ\www\59\include\functions.php on line 1202

    if (strpos($referrer['host'], 'www.') === 0)

    if ($referrer['host'] == $valid['host'] && preg_match('%^'.preg_quote($valid['path'], '%').'/(.*?)\.php%i', $referrer['path']))

http://fluxbb.org/development/core/tickets/998/#qy8ftuz22