andrejcremoznik on "[Plugin: Polylang] Language choose not storing session or cookie?"

@Chouby, this bit (core.php:486):

if (false === stripos($_SERVER['SCRIPT_NAME'], $GLOBALS['wp_rewrite']->index)) {
	$this->curlang = $this->get_preferred_language();
	return;
}

prevent the plugin from working correctly in my case. After commenting it out, everything worked flawlessly.

What is it for and is it really needed?