Retroactively cross-posting articles

[Lars Magne Ingebrigtsen]

Here's my problem: I run a mail-to-news gateway.  (<URL:
http://gmane.org/).  When people "cross-post" to several mailing
lists that are all being gated into Gmane, the second (and
subsequent) copies of the messages will be denied posting, since that
Message-ID has already been posted on Gmane.

Gmane currently just generates a new Message-ID for the denied
messages, but this breaks threading.

It would be nice if it were possible to retroactively cross-post a
message.  To be able to say "alter message MESSAGE-ID to have this
Newsgroups header and be cross-posted to these groups".  How hard
would it be to hack up something like this?

-- 
(domestic pets only, the antidote for overdose, milk.)
   larsi at gnus.org * Lars Magne Ingebrigtsen