Re: Provide an option to make thread summaries keep initial subject

[David Bremner <david@tethera.net>]

Thomas Schwinge <thomas@schwinge.name> writes:

> Hi!
>
> Regarding the following ideas -- from almost a decade ago ;-) -- is
> anyone aware of any work in that area?

[snip]

> Austin wrote:
>> I think this would be fantastic.  I've proposed unconditionally
>> showing the earliest subject before and it seems that people who
>> correspond mostly with those who have good threading etiquette would
>> prefer this change, but those who correspond with more people who use
>> 'reply' like an address book prefer the current behavior.

So just to be clear, when viewing threads with sort-order=oldest-first,
the initial subject is in fact show. So if I understand the request
correctly, the request is to decouple which subject is shown from the
sort-order?

> And then, especially, the following one would be very useful for me:
>
>> Another option, which I'd like to experiment with but haven't found
>> the time, is to show *all* distinct subjects for matched messages in a
>> thread (modulo "Re:", etc) in the summary buffer, probably on multiple
>> lines.  Since most threads only have a single unique subject, they
>> would appear just as they do now, but it would be clear when someone
>> (or something, like git) changed the subject mid-thread.  This
>> approach would be far more robust while retaining good usability, but
>> it would require more code than just changing our subject-picking
>> heuristic.
>
> I'm aware of notmuch Emacs UI 'notmuch-tree' and 'notmuch-unthreaded',
> but these are not quite what is desired here: too verbose, compared to
> the concise display variant of 'notmuch-search'.

I don't think anyone picked up on this.  It would probably require
augmenting the json / sexpr to list all the subjects. I guess the
existing machinery to collect authors (lib/thread.cc) could be copied /
generalized to collect subjects. There is also some question of what
constitutes a change in subject, but there are already some (probably
inadequate) heuristics in the library for that. Another issue is how to
return the subjects from the library. Currently the authors are returned
as a comma separated list, but I doubt that's what you want for
subjects. C being C, we'd probably have to settle for some char ** null
terminated array of pointers.