No Gnus 0.3 slower than Oort Gnus 0.24 spam handling

[Alberto L]

Hi all,

I recently upgraded from Oort 0.24 to No 0.30 and my spam handling has
become quite slow.  Here is my situation:

- I use nnfolder mail storage
my spam handling configuration (using bogofilter):
- splits spam into mail.spam.temp
- on exiting, spam in all groups is moved to mail.spam.save
- mail.spam.temp and mail.spam.save are spam groups
- the spam process destination for mail.spam.save is nil

When I enter mail.spam.temp to check for false spam positives, on
quitting it all spam-marked messages are moved to mail.spam.save.
This is quite slower with No 0.30 w.r.t. Oort 0.24 because,
apparently, both mail.spam.temp and mail.spam.save are written to
disk each time a single message is moved.  With Oort 0.24 as far as I
can understand both groups are written to disk only once.

I include some bits of my spam configuration:

  (setq
   spam-split-group "mail.spam.temp"
   spam-junk-mailgroups
   '("mail.spam.temp" "mail.spam.save")

   gnus-spam-process-newsgroups
   '(
     ("^mail\\.incoming\\.....-..-..$"
      ((spam spam-use-bogofilter)))
     ("^mail\\.spam\\.train$"
      ;; ((spam spam-use-blacklist))
      ;; ((ham spam-use-whitelist))
      ((ham spam-use-bogofilter))
      ((spam spam-use-bogofilter)))
     ("^mail\\.spam\\.save$"
      ((ham spam-use-bogofilter)))
     )

   gnus-spam-process-destinations
   '(
     ("^mail\\.spam\\.save$" nil)
     ("^mail\\..*$" "mail.spam.save")
     )

   gnus-ham-process-destinations
   '(
     ("^mail\\.spam\\..*$" "mail.incoming.nospam")
     )
   )

Greetings,
-- 
Alberto