bug#47431: Process Whois connection broken by remote peer.

[Gregory Heytings]

> > On Ubuntu 20.04, I'm using the self compiled git master version of 
> > Emacs. It seems that the whois client in Emacs only works for some 
> > specific domain names, for example gnu.org and emacs.org, but for 
> > others like facebook.com it just hangs and returns nothing. The 
> > following command will trigger the error:
> >
> > "M-x RET whois RET facebook.com"
>
> It doesn't hang here (I'm not on Ubuntu, though).  It times out:
>
>  open-network-stream: make client process failed: Connection timed out, 
> :name, Whois, :buffer, *Whois*, :host, rs.internic.net, :service, 43, 
> :nowait, nil, :tls-parameters, nil, :coding, nil
>
> If I try a different server, it does work:
>
>  C-u M-x whois RET facebook.com RET whois.crsnic.net RET
>
> This returns immediately with a large *Whois* buffer.
>
> Perhaps some network expert could tell why we use by default a server 
> that is less useful.

(I'm not a network expert, but...)

It is probably better to let the whois client select the appropriate 
server itself.  The current default whois-server-name (rs.internic.net) 
doesn't work at all, and although whois-guess-server is t, it doesn't work 
well.

The manpage of whois says: "This version of the whois client tries to 
guess the right server to ask for the specified object. If no guess can be 
made it will connect to whois.networksolutions.com for NIC handles or 
whois.arin.net for IPv4 addresses and network names."