About trackback charset

In wp-trackback.php:

$charset = $_POST[‘charset’];

$title = mb_convert_encoding($title, get_settings(‘blog_charset’), $charset);

So WP use the ‘charset’ field in post data as the from encoding. But in trackback() function (wp-includes/functions.php), it does not send a charset field in post data.

(Yes, it send a charset in Content-Type: … charset: , but that’s not enough. )