Mail splitting stopped working with Emacs 25

[Jarmo Hurri <jarmo.hurri@iki.fi>]

Greetings.

The subject describes the problem. I am getting a bit desperate here. I
have two questions. The first one is short and would solve the entire
problem. The second one describes the problem.

1. If anyone has a working imap mail splitting definition for Emacs 25
   which uses gnus-group-browse-foreign-server to subscribe to the imap
   groups I would like to see it. I can probably figure out my own
   version from it.

2. Now the _long_ version.

   In Emacs 24 I had the following way to subscribe to imap and split
   my mail.

   i. I subscribed to the imap boxes by evaluating

      (gnus-group-browse-foreign-server
        '(nnimap "mail"
           (nnimap-address "mail.server.com")
           (nnimap-stream ssl)
           (nnimap-server-port 993)))

   ii. Then in my .gnus I defined the equivalent of the following:

      (setq nnimap-inbox "INBOX")
      (setq nnimap-split-methods
       '(
        ("lists" "^\\(To\\|Cc\\):.*list")
        ("Spam" "^From:.*spamster")
        ("personal" "")))
        

   This stopped working in Emacs 25. The following thread examined some
   of the problems involved:

   https://lists.gnu.org/archive/html/bug-gnu-emacs/2015-07/msg00549.html

   Ok, so I set out to solve the problem. My FIRST EFFORT was to try to
   pass my splitting rules to gnus-group-browse-foreign-server,
   something along the lines of evaluating

      (gnus-group-browse-foreign-server
        '(nnimap "mail"
           (nnimap-address "mail.server.com")
           (nnimap-stream ssl)
           (nnimap-server-port 993)
           (nnimap-inbox "INBOX")
           (nnimap-split-methods
             '(
               ("lists" "^\\(To\\|Cc\\):.*list")
               ("Spam" "^From:.*spamster")
               ("personal" "")))))


   That resulted in really weird behaviour, with mail being split
   correctly when I first subscribed, but then all the mail going to
   "mail.misc" on subsequent restarts of gnus.

   SECOND TRY: use gnus-secondary-select-methods with a variable,
   something equivalent to

   (setq my-nnimap-split-methods
     '(
       ("lists" "^\\(To\\|Cc\\):.*list")
       ("Spam" "^From:.*spamster")
       ("personal" "")))
   
   (add-to-list 'gnus-secondary-select-methods
        '(nnimap "mail"
           (nnimap-address "mail.server.com")
           (nnimap-stream ssl)
           (nnimap-server-port 993)
           (nnimap-inbox "INBOX")
           (nnimap-split-methods my-nnimap-split-methods)))

    This gave me _no mail_: no imap boxes, no mail whatsoever, nothing
    even related to imap in buffer *Messages*. I have no idea why.

    THIRD TRY. My original splitting was not fancy, but the guy I
    referred to above had used it succesfully. So I converted my
    splitting rules to fancy form, and tried to browse the foreign
    server again:

    (setq nnimap-split-fancy
      '(|
	(to "list" "lists")
        (from "spamster" "Spam")
	"personal"
	))

     (gnus-group-browse-foreign-server
        '(nnimap "mail"
           (nnimap-address "mail.server.com")
           (nnimap-stream ssl)
           (nnimap-server-port 993)
           (nnimap-inbox "INBOX")
           (nnimap-split-methods 'nnimap-split-fancy)))

     Still no working splitting: all the mail gets split into box
     "mail.misc".

I would _really_ appreciate help here.

Jarmo