foreach ($_EXTRA_URL as $url_param)
$url_param = explode('=', $url_param, 2);
$s_hidden_fields[$url_param] = $url_param;
$s_search_hidden_fields[$url_param] = $url_param;
Missing hidden fields in search form
Pull Request on GitHub
For testing purposes, please specify the nature of the behavior this error causes (its pretty obvious what it should be)
A_Jelly_Doughnut: This should cause the same problems as described in http://tracker.phpbb.com/browse/PHPBB3-10319 as this ticket is only fixed partially.
Okay, it seems like http://tracker.phpbb.com/browse/PHPBB3-10319 was never fixed. The ticket introduced three blocks and all used the wrong variable name. The author of this ticket updated the ticket accordingly.