Hi all,

$ sudo dovecot --version 1.2.beta3

I just started using Dovecot a few weeks ago, and my client is also using the X-REFERENCES2 thread algorithm. The client is misbehaving when trying to list messages in my INBOX, but only when a threaded message exists. I have tracked it down to the thread index that Dovecot is returning, but the problem is only extant when using the X-REFERENCES2 thread algorithm. Here is a snippet of transcript from imap client that comes with Dovecot:

$ export MAIL=maildir:~/Maildir:INBOX=~/Maildir/INBOX $ /usr/lib/dovecot/imap <snip> 1 SELECT "INBOX" <snip> 2 THREAD X-REFERENCES2 UTF-8 ALL

• THREAD (0)(2)(1 3)(4) 2 OK Thread completed.

There are, in fact, only 4 messages in my INBOX, and the reference to (0) seems spurious. When I do the same test, but passing REFERENCES instead of X-REFERENCES2 Dovecot returns an index which I believe to be correct:

<snip> 2 THREAD REFERENCES UTF-8 ALL * THREAD (1 3)(2)(4) 2 OK Thread completed. <snip>

Is this the normal and expected behavior of X-REFERENCES2 that the client just needs to take into account, or is the reference to thread index (0) an error?

Thanks!

Nathan