KeyError during IMAP to IMAP sync of deleted msgs

[Dan Christensen]

Dan Christensen <jdc at uwo.ca> writes:

> Unfortunately, the problem is more serious than having to restart
> offlineimap.  After the sync finally completed, one message was missing
> from the local IMAP folder, and 55 messages were duplicated!

Tried from scratch again, and one message went missing and 29 were
duplicated.  Also lost a read mark.  The folder I'm trying to sync
has about 6000 new messages at the local end, and 0 at the remote
end.

The offlineimap man page says:

  OfflineIMAP is SAFE; it uses an algorithm designed to prevent mail
  loss at all costs.  Because of the design of this algorithm, even
  programming errors should not result in loss of mail.

Seems like the algorithm isn't working like it should, since twice
in a row now it has lost a message during a sync.  Or could dovecot
be to blame?

I saved a copy of dovecot's maildir at the local end from before and
after, and noticed that *all* the filenames changed.  Is this normal?

Dan