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.
the legacy style is a poorly executed attempt at Maildir++, so introduce
the latter for the sake of completeness. but most users will probably
just want to use subfolders without any additional dots.
move the unconditional addition of INBOX out ouf the function.
this makes it possible to move the folder check and addition to the
listing before the recursion, which seems clearer.
in the case of imap stores, the failure is bound to the server config,
not just the store config.
that means that the storage of the failure state needs to be private to
the driver, accessible only through a function.
simply make the code symmetrical to the inverse case.
note that the result will be sort of awkward, as the folders under Path
(and thus the subfolders of Inbox) don't start with a dot, while the
subfolders of these folders do. this needs to be addressed separately.
when we run into Inbox while listing Path, check whether Inbox is being
listed anyway, and just skip it if so, instead of listing it right away
and resetting LIST_INBOX (and thus having a calling order dependency).
USER (the authorization identity) specifies whom to act for.
AUTHNAME (the authentication identity) specifies who is acting (and
thus whose PASS is being used).
USER is derived from AUTHNAME if omitted, but apparently the
GSS-API module automatically adds the REALM, which is not helpful.
it appears to be common to set both USER and AUTHNAME to the same value,
so let's just do it as well.
REFMAIL: 20150407194807.GA1714@leeloo.kyriasis.com
the PassCmd will be typically non-interactive (or it will use a gui
password agent), so starting a new line just makes the progress counter
uglier. so make it configurable and default to no line break.
