[Dovecot] Cooperating with dovecot in its Maildir

[Timo Sirainen]

On Sat, 2011-01-29 at 12:04 -0600, Rob Browning wrote:
> >> I saw that, but I wasn't sure if the fact that a message might "receive
> >> a new UID" could be a problem.  
> >
> > It's a theoretical problem mostly, especially in your case. It's
> > mainly visible when doing stress testing with large maildirs. I doubt
> > in regular use it matters. Courier doesn't try to prevent it in any
> > way and it seems to have worked mostly ok.
> >
> >> Or is the UID supposed to change when the flags change?
> >
> > No.
> 
> OK, so it sounds like if we wanted to be completely safe, we probably
> need to know that we're in a dovecot Maildir, and then we need to know
> where to create the appropriate dovecot-uidlist.lock file whenever
> renaming files.

There's no good way to find out where the uidlist files are, if they're
not in the maildir itself. They typically are.

> Do you happen to know if the liblockfile (lockfile_create(3), etc.)
> .lock strategy is compatible with dovecot's approach?

Should be. It's possible though that in a future version there is
no .lock file but rather the uidlist is locked directly with fcntl.