Re: Bug tracker breaks rmail-next-same-subject

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 12 Dec 2008 15:25:51 -0800
> From: Don Armstrong <don@donarmstrong.com>
> 
> > > That's why References: and In-Reply-To: exist.
> > 
> > You are evidently assuming that everybody uses MUA that preserve
> > these headers as they should. The reality is a bit different.
> 
> There are loads of broken MUAs; that doesn't change the fact that
> they're broken. References: and In-Reply-To: are the primary way of
> tracking threads. In the absence of them, you can try to track threads
> using subject, but that's never the first option.

I don't want to memorize two different ways of following a subject.  I
have things to do with my time other than read emacs-devel and
bug-gnu-emacs.  As long as there are loads of broken MUAs, using the
Subject line will always be more reliable than references.  Until now.

Btw, the bug tracker seems to keep only one reference in References:,
which doesn't help too much to follow a thread by that.

> If you want to follow a thread, References: and In-Reply-To: are the
> way to do that; Subject: may approximate it, but it's never as
> accurate.

What other use cases will break it?  Until now, I didn't see any.