Channel: attempt inviting before errorring about needing at least half/op to invite someone

[Mikaela]

In several IRCds there are modes that allow everyone to invite users. On Ergo IRCd (which inspires opening this issue), free-invite is the default (without any modes) and thus Limnoria should just invite me to room on command, not complain to me that it needs halfop to do it (which is wrong). It can always see when there is a real error about the invite and then complain afterwards.

• The current (running) version of this Limnoria is 2021.07.16, running on Python 3.9.2 (default, Feb 28 2021, 17:03:44) [GCC 10.2.1 20210110]. The newest versions available online are 2021.06.15 (in master), 2021.07.16 (in testing).

• ergo-2.7.0

[progval]

Depends on #1483 (yes I opened that issue just because of this, but it has been on my mind for a while)

Relationale:

This would mean trying INVITE and waiting for ERR_CHANOPRIVSNEEDED from the server to send the error to the user. Unfortunately, this can't be done reliably without labeled-response, because many other events may cause ERR_CHANOPRIVSNEEDED at the same time, and that numeric doesn't have enough info to match what message caused it.

Because labeled-response handling in Limnoria is currently very clunky (see the REGISTER implementation in Services...), I'm unlikely to implement this before #1483 is resolved, as it provides a good way to implement this.