https://ircv3.net/specs/extensions/chathistory#isupport-tokens
The spec says they should be 'in order of decreasing preference'.
As currently the only backend is in-memory, this doesn't matter so I
picked `msgid` first (as it's less ambiguous); but this can be revisited
later if/when adding a backend which is more efficient with timestamps.
It means you can no longer modify eg parv[1] in-place with strtoken and such.
The main reason for this is that as a command handler you have no idea
where the arguments may come from. It could be from a do_cmd() with
read-only storage (eg a string literal) and so on.
It started with an experiment of how far I could get and how annoying the
side-effects would be, but they seem to be quite managable, so I'm
committing this stuff.
Hopefully this catches/solves some stupid bugs somewhere :)
from https://ircv3.net/specs/extensions/chathistory
Current status of the module in UnrealIRCd:
* A significant part of this is done and working
* Currently in modules.optional.conf to get test exposure,
not yet loaded by default.
* CHATHISTORY subcommands implemented: BEFORE, AFTER, LATEST, AROUND
* It does not implement the subcommand "BETWEEN" yet
* It does not announce or recognize the (draft) CAP's yet
* It does not announce the ISUPPORT token CHATHISTORY=xx yet
* Testcases need to be written to validate everything
* There will be bugs, now, and also while implementing the rest
in the days to come.