From: Tom von Alten (tom_vonalten@boi.hp.com)
Date: Thu Oct 14 1999 - 17:05:30 CDT
Daniel Stenberg writes:
> 1. The thread index requires a mail that is not a reply to start a
> thread with.
>
> 2. The function hashreplynumlookup() (struct.c:362) does it best
> to look up possible replies.
>
> 3. In the problematic mailbox we have identical subjects "Re:
> Beschwerde" in all three mails, but only one of them with a
> In-Reply-To: header.
...
> 4. All this taken together, mail 0 is considered the reply to
> message 2 and the other two are considered replies to mail 0.
>
> I really can't see any good way out from this. Other than not match that
> willingly on subjects, but that will make hypermail less effective when
> clients that don't support in-reply-to and similar are used.
>
> Anyone with ideas or suggestions around this?
I'm not exactly sure what you mean by #4, but it sounds like a circular
reference. Is that what made the thread disappear?
Without diving into the code, it occurs to me that there needs to be a
defined algorithm with no ties, and no unending lists. It seems like the
date (sure, but which one?!) should be a consideration. In the example you
give, the way out might be that we find 0 is a reply to 2, 1 is a reply to
0 and 2 is a reply to 0... but disallow that as circular. So, this thread
is
2
0
1
and go on.
As for suggestions, I have one that probably can't fly for v2, but
something to consider:
When I first started hacking v1.02 and the wrapper script a coworker
gave me, I worked to improve threading based on the subject field alone. I
quickly got lost in cross references in the hypermail code, and chose to
work on the wrapper shell script instead.
The general outline of what I did was to try to recognize and remove
prefixes (and variations in capitalization) and extract a string I called
the "thread" (title, if you will).
After trying various approaches to managing this, I ended up with a
separate file of threads which I use for comparison to incoming messages.
If I find a match, I stick "Re: " in front of the thread string, and feed
it to hypermail, which threads it by the subject.
It makes sense to strongly consider "In-reply-to" and it makes sense to
strongly consider the subject. At this point, I'd vote for whatever is
closer to "done." Broken threading is not too big a tragedy, as much as
we'd like it. (Missing threads need to be fixed, of course!)
Cheers,
_____________ Hewlett-Packard Computer Peripherals Bristol
Tom von Alten mailto:Tom_vonAlten@boi.hp.com
This posting is for informational purposes only.
It is not a statement of the Hewlett-Packard Co.