[NNTP] Extension snapshots 2

[Russ Allbery]

Russ Allbery <rra at stanford.edu> writes:
> Clive D W Feather <clive at demon.net> writes:

>> Actually, given this whole thing is aimed at solving one very restricted
>> problem, how about being prescriptive:

>>     The client MUST NOT send this command, and the server MUST NOT
>>     advertise the MODE-READER capability, after any other command except
>>     CAPABILITIES has been used in the session.

> Hm.  It's more complexity for the server to keep an internal state flag
> and know if other commands have been used in the session.  That part of
> this is kind of ugly; if it weren't for that, I'd like the idea.

And, actually, even worse than that, this says that the output of
CAPABILITIES may change in circumstances other than the places we've
documented that explicitly (AUTHINFO, STARTTLS, and MODE READER).  I don't
think that's a good idea; the CAPABILITIES output shouldn't vary except as
a result of specific commands that perform major state changes and are
documented as possibly changing the server capabilities.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>