gnus-thread-sort-by-most-recent-date not symmetric

[Ted Stern <dodecatheon@gmail.com>]

As you might have gathered from my last message, I'm getting back into
Gnus after a bit of an absence, and have been having trouble with my
local jury-rigged configuration.

I was just attempting to make threading look a bit like Gmail in
reverse:  sorting threads with most recently active emails down to the
bottom of the *Summary* buffer.  So I have this in my .gnus:

;;
;; More logical ordering within thread:
(setq gnus-sort-gathered-threads-function 'gnus-thread-sort-by-date)
;;
;; Like Gmail:  bubble most recently active threads to the bottom:
;;
(setq gnus-thread-sort-functions
      '(
        gnus-thread-sort-by-number
        (lambda (t1 t2)
          (not
           (gnus-thread-sort-by-most-recent-date t1 t2)
           )
          )
        )
      )

But this doesn't work quite as I'd expect.  Instead of sorting by the
most recent date within the thread, it seems to sort only by the root
of the thread.

If I use gnus-thread-sort-by-most-recent-date by itself, I get the
most recently updated thread at the top of the *Summary* buffer, so I
can't figure out why reversing the function isn't symmetric.

Any ideas?

Ted
-- 
 dodecatheon at gmail dot com
 Frango ut patefaciam -- I break so that I may reveal