[NNTP] Extension snapshots 2

[Russ Allbery]

Ken Murchison <ken at oceana.com> writes:

> OK, given that all we care about is the advertising of the capability,
> can we just rely on the base doc and remind people with my alternative
> text:

> "The capability list returned in response to a CAPABILITIES command
> received after authentication MAY be different that the list returned
> before authentication.  For example an NNTP server may not want to
> advertise support for a specific extension unless a client has been
> authenticated.  Likewise, servers are not permitted to advertise the
> MODE_READER capability after authentication (see X.X of [NNTP])."

The only reason why I'm leery of that approach is that sending MODE READER
after authentication could potentially break something (if you
authenticate to the transit server and then switch to the reader server,
for instance).  Of course, a client shouldn't send MODE READER unless
MODE_READER is advertised as a capability -- maybe that's all we need.

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