关于statusNet发中文邀请或者通知邮件时题头会产生乱码问题（续）

function cleanup_mail($string)
    {
        $string = str_replace(array("\r", "\n", "\r\n"), "", $string);
        $string = trim($string);
        return $string;
    }
function utf8_encode_c($string)
    {
        $charset = 'utf-8';
        $encoded_string = $string;
        if(strtolower($charset) == 'utf-8' && preg_match('/[\x00-\x08\x0b\x0c\x0e-\x1f\x7f-\xff]/', $string))
        {
            // Define start delimimter, end delimiter and spacer
            $end = "?=";
            $start = "=?" . $charset . "?B?";
 
            // Encode the string
            $encoded_string = base64_encode($encoded_string);
            $encoded_string = $start . $encoded_string . $end;
        }
        return $encoded_string;
    }
 
function mail_send($recipients, $headers, $body)
{
    // XXX: use Mail_Queue... maybe
    $backend = mail_backend();
    if (!isset($headers['Content-Type'])) {
        $headers['Content-Type'] = 'text/plain; charset=UTF-8';
        $headers['Subject'] = utf8_encode_c(cleanup_mail($headers['Subject']));
    }
    assert($backend); // throws an error if it's bad
 
    $sent = $backend->send($recipients, $headers, $body);
    if (PEAR::isError($sent)) {
        common_log(LOG_ERR, 'Email error: ' . $sent->getMessage());
        return false;
    }
    return true;
}