[Coco] Message Threading

[Tormod Volden]

On Wed, Aug 9, 2017 at 8:47 PM, James Ross wrote:
> It’s true, I’ve seen the issues that both John Linville and Tormod brought up … + I’ve seen people respond to a digest w/o even bothering to change the subject line so you have NO idea what thread that is!!

Replying to a digest will probably break things.

Conventionally, threading is based on mail headers (that the MUA
typically hides) like "In-Reply-To:". E.g. in Thunderbird you can do
ctrl-U to see the original message including headers. In GMail there
is a "Show Original" entry in the /message/ menu (next to the
right-hand Reply button).

If you post a message without any In-Reply-To header you will
technically start a new thread. If you answer normally to another
message, your MUA will automatically insert these headers.

>
> However, in this discussion, I’ve seen these threads called out
>
> - "Booting OS9 on my CoCo 3"
> - "GCC6809 cross compiler, assembler & linker"
>
> as being broken.   I use outlook.live.com which doesn’t do threading at all.  I just read the messages and delete them unless I think I’ll come back and respond.  And then later, I’ll delete those if I don’t.  I am relying on Pipermail archive to keep a historical record of the threads.
>
> http://pairlist5.pair.net/pipermail/coco/
>
> AND I just want to point out that on that site neither of two threads mentioned are broken. If Pipermail can figure out, then email clients should be able to.  Am I missing something?
>

To demystify, pipermail uses In-Reply-To and References headers /plus/
it falls back to match Subject lines:
https://mail.python.org/pipermail/mailman-users/2010-February/068844.html

Many MUAs rely on In-Reply-To headers only, which is technically
correct. Matching Subject: lines is heuristics that will sometimes
create false positives.

You can notice that the pipermail archive doesn't properly thread
messages without In-Reply-To, these messages get listed after another
message with the same subject but not necessarily the one to which the
sender wanted to reply.

Tormod

> However, I do notice that "MAME FDC Issue that can cause corruption" is broken once  ...
>
> James