Corrupt MIME articles without boundary parameter?

[Matthias Andree <ma@dt.e-technik.uni-dortmund.de>]

Hi,

I sometimes receive articles with munged headers that lack the boundary
parameter. The problem is something like this in the headers:

| Mime-Version: 1.0
| Content-Type: multipart/signed; micalg=pgp-sha1;
| Content-Disposition: inline
| User-Agent: Mutt/1.4i

I don't have "show body as plain text, in this buffer", and pressing C-d
is of no avail.

As we know mutt emits correct MIME stuff in this case, we can safely
assume the boundary parameter was munged by some transport software that
was unaware of folded lines (aka. continuation lines). One such piece of
broken software is BeroList before and excluding 3.0.

Would some kind volunteer soul of Gnus hacker provide either of the
following:

1. an insinuate-MIME function (maybe for article washing) that finds the
   first line to match ^--(.*)$ and use the captured string as boundary

alternatively:

2. treat the message as text/plain if the boundary parameter is missing

Of course, I'd prefer #1.

Being unaware of elisp and the Gnus environment and short of time to get
acquainted with that, I'm unable to do this myself now. Maybe in my next
life...

Many thanks in advance.

-- 
Matthias Andree