Bug in QueryBuilder::add() method, param $append has no effect for where/having DQL parts

$query->add('where', 'u.some = ?1');
$query->add('where', 'u.other = ?2', true);

if ($append && $isMultiple) {
    if (is_array($dqlPart)) {
        $key = key($dqlPart);
        $this->_dqlParts[$dqlPartName][$key][] = $dqlPart[$key];
    } else {
        $this->_dqlParts[$dqlPartName][] = $dqlPart;
    }
} else {
    $this->_dqlParts[$dqlPartName] = ($isMultiple) ? array($dqlPart) : $dqlPart;
}

$isMultiple = is_array($this->_dqlParts[$dqlPartName]);

private $_dqlParts = array(
    'distinct' => false,
    'select'  => array(),
    'from'    => array(),
    'join'    => array(),
    'set'     => array(),
    'where'   => null,
    'groupBy' => array(),
    'having'  => null,
    'orderBy' => array()
);