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
that pattern may very well expand to INBOXNOT, which would naturally
live under Path, so we need to look into the Path. of course, this
actually makes sense only if there *is* a Path, and complaining about
it being absent is backwards.
the idea that this is even possible was based on an incomplete reading
of the imap spec.
however, the infrastructure for supporting multi-char delimiters as such
is retained, as the Flatten option can be used with them.
recycling server connections skips everything up to setting up the
prefix (Path/NAMESPACE). "everything" should obviously include enabling
compression, as that must be done at most once per connection.
any structures may be invalid after callback invocation.
this has the side effect that the socket write callback now returns
void, like all other callbacks do.
the synchronous writing to the socket would have typically invoked the
write callback, which would flush further commands, thus recursing.
we take the easy way out and make it fully asynchronous, i.e., no data
is sent before (re-)entering the event loop.
this also has the effect that socket_write() cannot fail any more, and
any errors will be reported asynchronously. this is consistent with
socket_read(), and produces cleaner code.
this introduces a marginal performance regression: the maildir driver is
synchronous, so all messages (which fit into memory) will be read before
any data is sent. this is not considered relevant.
