Getting the right root mail of the thread

[Felipe Contreras]

On Sun, Nov 3, 2013 at 2:35 PM, Jesse Rosenthal <jrosenthal at jhu.edu> wrote:
> Jani Nikula <jani at nikula.org> writes:
>> I think it's actually worse than what your example demonstrates. It's
>> the subject of the newest/oldest *matching* message that gets used. In
>> your example, the first/last messages in the thread apparently match
>> your query.
>
> The behavior is there because subjects frequently change in long
> threads, and this allows the subject to refer to the most recent unread
> message (if we're sorting in the default order). The
> reason I requested and wrote in this behavior five years ago or so (my
> only c contribution ever) was that numerous business associates would
> keep email lists by replying and changing the subject. This is *very*
> common outside of programming circles. Even in programming circles,
> subjects frequently change on mailing list (with a "[was: ...]"
> appended).

Yes but how important is it to keep track of that?

I say it is much more important to track threads like this properly:

  foobar patch 0 (usually a summary/overview)
  +-foobar patch 1
  | +-comment on patch 1
  +-foobar patch 2
  +-foobar patch 3
  | +-comment on patch 3
  +-foobar patch 4
  +-foobar patch 5

But fine, let's concentrate on the common user scenario (which is not
common for notmuch users at all). We can have a thread like this:

  No work on Friday
  + Shall we go for some beers? (was: No work on Friday)
  + What about project X? (was: No work on Friday)

So which is the correct summary of the thread? The fact of the matter
is that we are talking about three threads now.

Gmail does this correctly. Each time the subject is changed, it's
considered a new thread.

> The current behavior can be annoying, but the old behavior could make
> the MUA quite unusable in a number of circumstances. (And yes, an MUA
> that fails on reading mail from senders with bad emailing practices is
> unusable for me.)

This is rhetorical warfare. It's wouldn't be "failing on reading mail".

If displaying the original subject is failing, then we might be
failing when searching with older first. Why would the order of the
search affect the thread summary?

> Maybe there should be a "show original subject" toggle? That wouldn't be
> too hard, though it would require another call to the library and
> regenerating the search results.

Yes. I say it should be a property of the query. I don't see why
anybody would want it any other way, but it wouldn't hurt to make it
an option.

-- 
Felipe Contreras