Re: [Nmh-workers] problem with mhshow after mhfixmsg

[Ken Hornstein]

>i'm having a problem with mhshow showing some of the parts
>of a message, but only after the message has been run through
>mhfixmsg.
>
>before i start debugging mhshow (which i'm willing to do, though
>it will take me a while), i want to be sure that the output of
>mhfixmsg is valid MIME.

Okay, so I took a look at this and I can reproduce it.  It's not mhfixmsg's
fault.

The fault is because of the ... unusual (but valid) structure of this
message, and the logic inside of show_multi_internal().

At the top level, this message has a multipart/alternative, and enters
show_multi_internal().  This sets alternating, but not alternate, which
is correct:

/*
 * alternate   -> we are a part inside an multipart/alternative
 * alternating -> we are a multipart/alternative
 */

The two sub-parts of the top-level multipart/alternative are a text/plain
and a multipart/related.

The multipart/related is decended into.  It contains a multipart/alternative
and multiple image/jpegs.  The sub-parts of THAT multipart/alternative are
a text/plain and text/html.  Both of the attempts to view the those
parts fail (because part_ok() returns false for both of them).

But THAT causes show_multi_internal() to return NOTOK.  Why?
Well, alternate is passed down as "true" from the top-level
multipart/alternative type.  The default return code for
show_multi_internal() is set to NOTOK if alternate is set.
And when processing the multipart/related, alternate is true (because
we're under the top-level multipart/alternative) but alternating
is false (because multipart/related is not an alternate part itself).
That short-circuits the multipart/related processing and it bails
out at that point; that bubbles up to the top-level alternative part
and you get the resulting error.

Are you confused?  I sure was.

As for a fix ... crud, I don't know.  I am reluctant to mess with that
alternative part processing, as it's kind of a mess (I was planning on
rototilling it for the next release).

--Ken