I just wasted some time when someone uploaded three patches to the tracker, but
only added a comment to the first one. This is reasonable. But because the
tracker only lets you upload one file, and suppresses mail when no message is
added, I only received an email with an attachment of the first file.

IMO we either shouldn't be sending attachments out (which would have forced me
to go to the tracker so I'd seen that there were three patches) or we should add
some JS to allow uploading multiple files in one request (like gmail does with
attachments).

> IMO we either shouldn't be sending attachments out (which would have forced me
> to go to the tracker so I'd seen that there were three patches) or we should add
> some JS to allow uploading multiple files in one request (like gmail does with
> attachments).

Alternatively, would it work if one email message had been sent per
additional attachment?

Yes, that would work too, and is probably easiest.

Currently a mail is sent even when a single file with no comment is added, and it's also possible to send several files at once via email (see e.g. http://bugs.python.org/msg171305), so I think this can be considered resolved.