Re: possible new sort option

[andré <andr55 laposte net>]

Le 2018-08-06 à 19:40, Peter Bloomfield a écrit :
> On 08/05/2018 11:35:26 AM Sun, Peter Bloomfield wrote:
> …
> > A new GitLab issue[0] has been opened to continue the discussion, and 
> > a new branch (thread-date) has a modified sort algorithm, with threads 
> > sorted by the date of the most recent message in the thread (its 
> > 'thread-date'). Testing and comments welcome!
> …
> > [0] https://gitlab.gnome.org/GNOME/balsa/issues/4
>
> Replying to myself, to keep the nesting from exploding☺
>
> I take it as a consensus that thread-date-sorting should be 
> implemented--right?

Haven't seen any dissenting opinions
> Questions:
> 1. Should it replace head-date-sorting, or be a preference item 
> (defaulting to thread-date)?

Replacing would keep it much simpler for (especially new) users.
Then the questions becomes threading or not.

> 2. Should we add an option to *not* gather threads by subject?

Would favour only by message id and "not* a fall-back by subject, to 
avoid the problem you outline below.
Having an occasional message shown outside its' thread is much less of a 
problem.
An option makes it more complicated.  If it exists, the default should 
be to *not* fall-back to subject.

> 3. Do we need simple threading?

One threading method is less confusing.
> AFAICT these are independent decisons.

Indeed.

To keep things in perspective re: JWZ algorithms, when JWZ was still 
active in the computer field, memory was much more expensive, disks much 
slower.
Now an entire mbox (or other) mail file can be quickly loaded into 
memory, so his performance tweaks become less important.

> Background on question 2: threading ('JWZ threading', but just 
> 'threading' if we drop 'simple') first uses the 'References' and 
> 'In-Reply-To' headers to construct threads. These depend on messages 
> having a 'Message-ID' header, which seems to be universal, but still not 
> mandatory (as of RFC 5322). To allow for the possibility that some 
> message in the thread did not have a msg-id, or that some mailer did not 
> use it to create a 'References' header, JWZ's algorithm then merges 
> ('gathers') threads that have matching 'Subject' headers. The downside 
> of the strategy is that unrelated messages with common subjects like 
> 'New bug' or 'Question about the test' get threaded together.
>
> Peter
another 2¢
--
André