[split] Bug in new form validation?

/that same in email.php library/

public function valid_email($str)
{
if (function_exists('idn_to_ascii') && preg_match('#\A([^@]+)@(.+)\z#', $str, $matches))
{
 if (defined('INTL_IDNA_VARIANT_UTS46'))
 {
  $domain = is_php('5.4')
  ? idn_to_ascii($matches[2], 0, INTL_IDNA_VARIANT_UTS46)
  : idn_to_ascii($matches[2]);
  $str = $matches[1].'@'.$domain; 
 } else {
  $str = $matches[1].'@'.idn_to_ascii($matches[2]); 
 }
}

return (bool) filter_var($str, FILTER_VALIDATE_EMAIL);
}