CodeIgniter框架下载辅助函数的一个小bug

        if (strpos($_SERVER[‘HTTP_USER_AGENT‘], "MSIE") !== FALSE)
        {
            header(‘Content-Type: ‘.$mime); // <---1)这里
            header(‘Content-Disposition: attachment; filename="‘.$filename.‘"‘);
            header(‘Expires: 0‘);
            header(‘Cache-Control: must-revalidate, post-check=0, pre-check=0‘);
            header("Content-Transfer-Encoding: binary");
            header(‘Pragma: public‘);
            header("Content-Length: ".strlen($data));
        }
        else
        {
            header(‘Content-Type: ‘.$mime); // <---2)这里
            header(‘Content-Disposition: attachment; filename="‘.$filename.‘"‘);
            header("Content-Transfer-Encoding: binary");
            header(‘Expires: 0‘);
            header(‘Pragma: no-cache‘);
            header("Content-Length: ".strlen($data));
        }

        if (strpos($_SERVER[‘HTTP_USER_AGENT‘], "MSIE") !== FALSE)
        {
            header(‘Content-Type: "‘.$mime.‘"‘);
            header(‘Content-Disposition: attachment; filename="‘.$filename.‘"‘);
            header(‘Expires: 0‘);
            header(‘Cache-Control: must-revalidate, post-check=0, pre-check=0‘);
            header("Content-Transfer-Encoding: binary");
            header(‘Pragma: public‘);
            header("Content-Length: ".strlen($data));
        }
        else
        {
            header(‘Content-Type: "‘.$mime.‘"‘);
            header(‘Content-Disposition: attachment; filename="‘.$filename.‘"‘);
            header("Content-Transfer-Encoding: binary");
            header(‘Expires: 0‘);
            header(‘Pragma: no-cache‘);
            header("Content-Length: ".strlen($data));
        }