<DKIM> Re:[offlineimap] Duplicates of messages copied from remote to local (#174)

[Peter Lewis]

Hi all,

A long time ago, in a galaxy far, far away.... I was attempting to do a
git bisect on an intermittent issue I am having with OfflineIMAP. The
symptom, is that once every now and again (sometimes days between
issues, sometimes twice in one day), OfflineIMAP would redownload the
entire folder, creating duplicate messages. I would then have to remove
duplicates (usually by asking Mutt to tag them using ~=).

I attempted to do a bisect before, but messed something up, and ended up
in an unlikely commit.

I've finally finished another bisect process. Note that since it's an
intermittent and seemingly randomly triggered issue, I marked a commit
as good after about a week or two after using it with no problems. So it
is possible there is some uncertainty in the process.

This time, I ended up at this commit being the first bad one:

https://github.com/OfflineIMAP/offlineimap/commit/9e63fa3784b8adc7b1dd28871ec5e80404d32b12

Now to me, this looks quite plausible, because the comments refer to
forgetting everything we know about messages.

This happens against both a Dovecot IMAP server and an Exchange server
working in IMAP mode.

I hope this is of some help.

Peter.