Re: Broken threading [was: Unbelievable.]

["J.B. Moreno" <planb@newsreaders.com>]

In article <m3vg6v8j0u.fsf@jeeves.decathlon>, 
 Tom Hardy <rhardy@mailandnews.com> wrote:

Sorry for the late reply, was offline for a week and then didn't read
the group for a week..

> "J.B. Moreno" <planb@newsreaders.com> writes:

> > That might work -- then again it might not.  I once did some local
> > gatewaying in order to read a mailing list with a threaded view, and
> > the only thing that was reliable was that programs repeated their
> > mistakes.  You are describing a "generic" method, which did indeed
> > work most of the time, but I had to have a whole bunch of special
> > cases (it wouldn't surprise me to learn that some of them were
> > developed by throwing darts to see what they should do),
> 
> I thought I would look at cases just for fun.  Tell me if I am all
> wet or otherwise wasting my time.
> 
>    I.  Mailer updates References and In-Reply-To, in which case they
>        both work, but references are more versatile.  In this case,
>        In-Reply-To will be identical to the last reference.
> 
>   II.  Mailer does neither.  Anything goes, but it is likely to look
>        like the first case.
> 
>  III.  Mailer updates In-Reply-To, ignores References.  In-Reply-To
>        will not be found in References.
> 
>   IV.  Mailer updates References, ignores In-Reply-To.  In-Reply-To
>        will be found in References, but it won't be the *last*
>        reference.  (Does this happen?)

Yes, don't ask me why.

>    V.  Other cases, such as one or the other header (or both) is
>        missing.

Skipping the fact that V covers everything, I-IV is pretty much what
you'd expect and is pretty much what *most* mailers do -- but it's by
no means certain.

One of the special cases that I had to keep an eye out for was where
In-Reply-To was accurate, but References wasn't (I remember two
variation on that, one where the precursor was simply left off, and one
where it was inserted as the 2nd id in the References header, which
required an especially stupid programmer IMO).  Basically anything can
go wrong.

And then there's stupid users who for some reason reply to a message
and will manually cut-n-paste so that it appears to be a reply to
another message (and no, I don't mean where they are replying to two
messages at once), which you have to watch out for because you don't
want to mistake it for something else and try to fix it based upon the
client.

-- 
J.B. Moreno