mailboxes with mostly messages with no Message-Id (such as Drafts and
Templates) cannot recover the usual way.
this patch implements a statistical method. as such, it has a (very)
slight chance to yield a false positive which would subsequently clobber
actual messages (specifically, the ones which were not sufficient to
throw off the algorithm). it would be possible to be even stricter, but
then any actual modification of the box would make the algorithm fail.
and even in this case, it would be still possible that even though the
UIDs match (and thus nothing gets deleted), the actual messages are in
reality different (though this is ridiculously unlikely).
the added tolerance doesn't help with stores which are synced seldomly,
as too much is likely to happen in the mean time.
*** actually make it stricter?
when syncing flags but not re-newing non-fetched messages, there is no
need to query the message size for all messages, as the old ones are
queried only for their flags.
instead of a single hard-coded branch, use a generic method to split
ranges as needed.
this is of course entirely over-engineered as of now, but subsequent
commits will make good use of it.
turns out the comment advising against it was bogus - unlike for
memcmp(), the standard does indeed prescribe that the memchr()
implementation may not read past the first occurrence of the searched
char.
if AuthMechs includes more than just LOGIN and the server announces any
AUTH= mechanism, we try SASL. but that can still fail to find any
suitable authentication mechanism, and we must not error out in that
case if we are supposed to fall back to LOGIN.
specifically, if AuthMechs included more than just LOGIN (which would be
the case for '*') and the server announced any AUTH= mechanism, we'd
immediately error out upon seeing it, thus failing to actually try
LOGIN.
the number was chosen to make queries more comprehensible when the
server sends no UIDNEXT, but it appears that such insanely large UIDs
actually show up in the wild. so send 32-bit INT_MAX instead.
note that this is again making an assumption: that no server uses
unsigned ints for UIDs. but we can't sent UINT_MAX, as that would break
with servers which use signed ints. also, *we* use signed ints (which is
actually a clear violation of the spec).
it would be possible to special-case the range [1,inf] to 1:*, thus
entirely removing arbitrary limits. however, when the range doesn't
start at 1, we may actually get a single message instead of none due to
the imap uid range limits being unordered. this gets really nasty when
we need to issue multiple queries, as we may list the same message
twice.
a reliable way around this would be issuing a separate query to find the
actual value of UID '*', to make up for the server not sending UIDNEXT
in the first place. this would obviously imply an additional round-trip
per mailbox ...
trashing many messages at once inevitably overtaxes m$ exchange, and the
connection breaks. without any progress tracking, it would restart from
scratch each time, which would lead to a) it never finishing and b) many
copies of the messages in the trash.
full transactions as we do for "proper" syncing would be over the top,
as it's not *that* bad if some messages get duplicated in the trash. so
we record only the messages for which trashing completed, thus allowing
some overlap between the attempts.
turns out i misread the spec in a subtle way: while all other folders
are physically nested under INBOX, the IMAP view puts them at the same
(root) level. to get them shown as subfolders of INBOX, they need to
have _two_ leading dots.
this also implies that the Maildir++ mode has no use for a Path, so
reject attempts to specify one.
the mbsync manual says explicitly that the system's default certificate
store should *not* be specified.
however, the isync manual talked about CA certificates, which is (and
always was) exactly wrong.
also adjust both .sample rc files.
flock() may be implemented via fcntl(), which may cause the process to
deadlock itself when trying to apply both types of locks. this is the
case even on linux when the file lives on NFS.
it's unlikely that anything except mbsync would try to access the
.uidvalidity files anyway, so there is no point in trying to be
compatible with anything else ...
REFMAIL: uddy4g589ym.fsf@eismej-u14.spgear.lab.emc.com
it is legal for an email system to simply change the case of rfc2822
headers, and at least one imap server apparently does just that.
this would lead to us not finding our own header, which is obviously not
helpful.
REFMAIL: CA+fD2U3hJEszmvwBsXEpTsaWgJ2Dh373mCESM3M0kg3ZwAYjaw@mail.gmail.com
Oswald Buddenhagen
Anton Khirnov