kohana/core — pull request #512 by Yahasana (2014-07-04 08:10:24+00:00)
Title: don't empty the error message

refer from the menu: [htmlspecialchars](http://cn2.php.net/htmlspecialchars#refsect1-function.htmlspecialchars-returnvalues)
> If the input string contains an invalid code unit sequence within the given encoding an empty string will be returned