TL;DR: supports for casemapping, now logs are saved in
casemapped/canonical/tolower form
(eg. in the #channel directory instead of #Channel... or something)
== What is casemapping? ==
see <https://modern.ircdocs.horse/#casemapping-parameter>
== Casemapping and multi-upstream ==
Since each upstream does not necessarily use the same casemapping, and
since casemappings cannot coexist [0],
1. soju must also update the database accordingly to upstreams'
casemapping, otherwise it will end up inconsistent,
2. soju must "normalize" entity names and expose only one casemapping
that is a subset of all supported casemappings (here, ascii).
[0] On some upstreams, "emersion[m]" and "emersion{m}" refer to the same
user (upstreams that advertise rfc1459 for example), while on others
(upstreams that advertise ascii) they don't.
Once upstream's casemapping is known (default to rfc1459), entity names
in map keys are made into casemapped form, for upstreamConn,
upstreamChannel and network.
downstreamConn advertises "CASEMAPPING=ascii", and always casemap map
keys with ascii.
Some functions require the caller to casemap their argument (to avoid
needless calls to casemapping functions).
== Message forwarding and casemapping ==
downstream message handling (joins and parts basically):
When relaying entity names from downstreams to upstreams, soju uses the
upstream casemapping, in order to not get in the way of the user. This
does not brings any issue, as long as soju replies with the ascii
casemapping in mind (solves point 1.).
marshalEntity/marshalUserPrefix:
When relaying entity names from upstreams with non-ascii casemappings,
soju *partially* casemap them: it only change the case of characters
which are not ascii letters. ASCII case is thus kept intact, while
special symbols like []{} are the same every time soju sends them to
downstreams (solves point 2.).
== Casemapping changes ==
Casemapping changes are not fully supported by this patch and will
result in loss of history. This is a limitation of the protocol and
should be solved by the RENAME spec.
Previously we dropped all TAGMSG as well as any client message tag sent
from downstream.
This adds support for properly forwarding TAGMSG and client message tags
from downstreams and upstreams.
TAGMSG messages are intentionally not logged, because they are currently
typically used for +typing, which can generate a lot of traffic and is
only useful for a few seconds after it is sent.
Previously, we only considered channel modes in the modes of a MODE
messages, which means channel membership changes were ignored. This
resulted in bugs where users channel memberships would not be properly
updated and cached with wrong values. Further, mode arguments
representing entities were not properly marshaled.
This adds support for correctly parsing and updating channel memberships
when processing MODE messages. Mode arguments corresponding to channel
memberships updates are now also properly marshaled.
MODE messages can't be easily sent from history because marshaling these
messages require knowing about the upstream available channel types and
channel membership types, which is currently only possible when
connected. For now this is not an issue since we do not send MODE
messages in history.
User channel memberships are actually a set of memberships, not a single
value. This introduces memberships, a type representing a set of
memberships, stored as an array of memberships ordered by descending
rank.
This also adds multi-prefix to the permanent downstream and upstream
capabilities, so that we try to get all possible channel memberships.
- Add RPL_ISUPPORT support with CHANMODES, CHANTYPES, PREFIX parsing
- Add support for channel mode state with mode arguments
- Add upstream support for RPL_UMODEIS, RPL_CHANNELMODEIS
- Request channel MODE on upstream channel JOIN
- Use sane default channel mode and channel mode types
We now store SASL credentials in the database and automatically populate
them on NickServ REGISTER/IDENTIFY.
References: https://todo.sr.ht/~emersion/jounce/10
