automatic MIME decoding in rmail

[Evil Boris]

I have been caught several times by the following.  Email comes with
the content-type message header

---------
Content-Type: text/plain;
        format=flowed;
        charset="koi8-r";
        reply-type=original
---------

Notice that CHARSET specifier does not immediately follow
"text/plain"---there is a FORMAT specification intervening in between.
For example hotmail.com sends such messages and several other
services.  (I have not been able to determine from reading the spec if
this is allowed by the standard.  Not sure how relevant that is
though.)  Emacs does not decode the charset correctly correct, because
of the following:

(defvar rmail-mime-charset-pattern
  "^content-type:[ ]*text/plain;[ \t\n]*charset=\"?\\([^ \t\n\";]+\\)\"?"
  "Regexp to match MIME-charset specification in a header of message.
The first parenthesized expression should match the MIME-charset name.")

I guess the fix is to replace [ \t\n]* with a pattern matching any
number of intervening specifications.  Not sure what form they should
take, so will leave that for an expert.

Thank,
        --Boris