ActionMailer: attachments with utf8 filenames?

I’m constructing messages with a file attachment. If the file
attachment has a name with accented characters, it gets mangled.
Looking at the generated email, at times it looks like it’s being
encoded as Japanese (*=iso-2022-jp’ja’) or more accurately, the name
is getting url encoded and the mailer prefixes it as being iso-2022-jp
so the name doesn’t get decoded properly by the email client.

Is there any way to get this to work? In the meantime, I found some
code to convert the filenames to ascii (lossy of course) but I’d like
a more permanent solution.

Thanks.

Paul Kim