Suboptimal querying 6to4 ip6.arpa. subdomains

[ppisar]

whois-5.3.0 addess support for ip6.arpa subdomain, but it fails to compute IPv4 address from a 6to4 IPv6 address. See the "0.0.0.0" in this output:

$ ./whois c.b.9.0.6.6.9.5.2.0.0.2.ip6.arpa.

Querying for the IPv4 endpoint 0.0.0.0 of a 6to4 IPv6 address.

No whois server is known for this kind of object.

Please note that 6to4 2002:/16 prefix is somewhat deprecated because ICANN stopped accepting them as NS values and NRO stopped delegating 2.0.0.2.ip6.arpa. subdomains. Despite that I think whois client could do better and compute the corresponding IPv4 address correctly as done with direct IPv6 address query:

$ ./whois 2002:5966:9bc::

Querying for the IPv4 endpoint 89.102.9.188 of a 6to4 IPv6 address.

% This is the RIPE Database query service.