Re: threading display strange

[Tassilo Horn <tsdh@gnu.org>]

Uwe Brauer <oub@mat.ucm.es> writes:

Hi Uwe,

> I just realised that the following is odd:
>
> []{ } 57606 [ Uwe Braue] Uwe Brauer [[CV] (was: [Amnu 19]) ] Sun, 28 Apr 2019
> 11:30:41 +0200 8.8k 6
> []{ }O 57585 [ tex-d-l-r] tex-d-l@li [tex-d-l Nachrichtenkompil] Sun, 28 Apr
> 2019 00:00:07 +0200 13k 165
> []{ }O 57593 [ users ] oub@mat.uc [Subject: Digest of users@] Sun, 28 Apr 2019
> 08:00:27 +0000 (UTC) 38k 11
> []{ } . 57604 [ Gestión d] oub@mat.uc [COMUNICADO AUTOMÁTICO DE ] Sun, 28 Apr
> 2019 11:13:27 +0200 (CEST) 5.0k 32
> []{ } 57608 [ Uwe Braue] Uwe Brauer [Re: [Amnu 19] ] Sun, 28 Apr 2019 11:31:33
> +0200 11k ?
>
> Why is  57606 displayed before  57585? 

Well, since you didn't tell us how you've configured sorting, I assume
you are using the defaults, and that would mean sorting by article
number.

--8<---------------cut here---------------start------------->8---
gnus-thread-sort-functions is a variable defined in ‘gnus-sum.el’.
Its value is
(...)
Original value was 
(gnus-thread-sort-by-number)

  This variable may be risky if used as a file-local variable.

Documentation:
List of functions used for sorting threads in the summary buffer.
By default, threads are sorted by article number.

Each function takes two threads and returns non-nil if the first
thread should be sorted before the other.  If you use more than one
function, the primary sort function should be the last.  You should
probably always include ‘gnus-thread-sort-by-number’ in the list of
sorting functions -- preferably first.  Also note that sorting by date
is often much slower than sorting by number, and the sorting order is
very similar.  (Sorting by date means sorting by the time the message
was sent, sorting by number means sorting by arrival time.)

...
--8<---------------cut here---------------end--------------->8---

Especially, the last sentence might give a clue.  I think with NNTP
(usegroups) the article number really exists on the server, so it's
"time the message was received on that nntp server".  But with IMAP
(mail) the number is assigned by Gnus, and then it basically gives the
order in which you've downloaded the messages, and that's not really
chronological.

Bye,
Tassilo