Re: Message shows up in wrong thread

[Ralph Fox]

On Sun, 29 Sep 2013 10:37:13 -0700, Evan Platt wrote:

> So I've seen this quite a bit - a message thread will show under the
> wrong 'thread'.


In a nutshell, hash collision.

Agent does not actually compare the MIDs when threading. Agent
hashes the MIDs to numbers, and Agent compares the hash numbers.
Occasionally two different MIDs will have the same hash number,
and that is when mis-threading can occur.

For headers without bodies Agent does not even store the MIDs
from the References header. Agent stores only the hash numbers.

This is a very old problem going back many years.
http://groups.google.com/groups/search?as_epq=hash+collision&num=30&sitesearch=groups.google.com&as_ugroup=alt.usenet.offline-reader.forte-agent



> Here's just one example.
> Subject: Re: HEY EAGLE
> Date: Sun, 29 Sep 2013 01:21:55 -0700
> Organization: Checkmate's Discount House of Spatulas
> Lines: 40
> Message-ID: <6u5dg5....@news.alt.net>
>
> Has this message showing under it in the thread:
>
> From: "Brian H��" <br...@invalid.absey-vine.co.uk.invalid>
> Newsgroups: 24hoursupport.helpdesk
> References: <c1svvm$15t$1$830f...@news.demon.co.uk>
> Subject: Re: explorer opening by default
> Lines: 57
> X-Priority: 3
> X-MSMail-Priority: Normal
> X-Newsreader: Microsoft Outlook Express 6.00.2800.1158
> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165
> Message-ID: <8wn0c.15434$gC2....@newsfe5-gui.server.ntli.net>
> Date: Sun, 29 Feb 2004 15:26:36 -0000
>
> (and then all the messages in THAT thread appear below too).
>
> Totally different subject, no linked message iD. I can provide others,
> but any suggestions?


Both <6u5dg5....@news.alt.net> and <8wn0c.15434$gC2....@newsfe5-gui.server.ntli.net>
have the same hash number, -31766669.


> Running 7.20, Win 8.1.


--
Kind regards
Ralph

[Ralph Fox]

On Mon, 30 Sep 2013 07:50:04 +1300, Ralph Fox wrote:

> Both <6u5dg5....@news.alt.net> and <8wn0c.15434$gC2....@newsfe5-gui.server.ntli.net>
> have the same hash number, -31766669.

Typo. What I meant to write was, both <6u5dg5....@news.alt.net> and
<c1svvm$15t$1$830f...@news.demon.co.uk> have the same hash number, -31766669.


For what it's worth, <8wn0c.15434$gC2....@newsfe5-gui.server.ntli.net> has
hash number -4591194.


--
Kind regards
Ralph

[Ralph Fox]

On Sun, 29 Sep 2013 20:57:42 -0700, Evan Platt wrote:

> Thanks, I'll enable "Start a new thread"... and see if that resolves
> it.
>
> looks like it's not retroactive, so I need to delete headers and start
> over?


It is retroactive, but it does not recalculate the threading right away.

Change the message list to a non-threaded sort, then change it back
to threaded. No need to delete headers and start over.


--
Kind regards
Ralph