bug#21462: 25.0.50; Gnus thread gathering and sorting inverted

[Lars Ingebrigtsen <larsi@gnus.org>]

Michael Welsh Duggan <mwd@md5i.com> writes:

> I have been attempting to implement the following use case:
>
> I have a gnus group that receives messages with subjects that look sort
> of like this:
>
> Some title, part 1, by X
> Some title, part 2, by X
> Some other title, part 32, by Y
>
> I gather these into threads by title using my own simplification
> function which I add to `gnus-simplify-subject-functions' in this
> group.  I also set `gnus-thread-hide-subtree' to `t' in this group, so
> each title takes up one Summary line.
>
> I then want to sort these threads by the *latest* message in the
> thread.  Thus, when a new part is received, the entire thread shows up
> as "newer".  To do this, I created by own function to set
> `gnus-thread-sort-functions' to.  This looks like this:
>
> (defun md5i-thread-sort-by-most-recent-date-reverse (h1 h2)
>   (<= (gnus-thread-latest-date h1) (gnus-thread-latest-date h2)))
>
> Unfortunately, this fails in many cases due to the fact that
> `gnus-summary-prepare' gathers thread after sorting threads.  In my case
> I need the reverse, and I think that the reverse always makes sense.  I
> have a patch which does this, and has been working for me for half a
> year or so.  I suggest you add this or an equivalent change to Gnus.
> Feel free to rewrite this patch completely.  I wrote it long enough ago
> that I do not remember why I needed to create `gnus-make-threaded-sort'.

There is a separater `gnus-sort-gathered-threads-function' -- doesn't it
do what you want it to?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no