[dns-operations] RFC7816 - do not remove

[Florian Weimer]

On 12/18/2017 09:15 AM, T.Suzuki wrote:
> I remember that this ENT returned NXDOMAIN.

(ENT == empty non-terminal)

Doesn't this explain it?  With RFC 7816, the name is actually queried, 
the response would be cached, and the subtree beneath it could be pruned 
if the response is NXDOMAIN?

Thanks,
Florian