    public static function autoload($class) {
        $file = HTMLPurifier_Bootstrap::getPath($class);
        if (!$file) return false;
        // Technically speaking, it should be ok and more efficient to
        // just do 'require', but Antonio Parraga reports that with
        // Zend extensions such as Zend debugger and APC, this invariant
        // may be broken.  Since we have efficient alternatives, pay
        // the cost here and avoid the bug.
        require_once HTMLPURIFIER_PREFIX . '/' . $file;
        return true;
    }
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.