FreeBSD -- Incorrect handling of zero-length RDATA fields in named(8)

Problem description:

The named(8) server does not properly handle DNS resource records where
the RDATA field is zero length, which may cause various issues for the
servers handling them.
Resolving servers may crash or disclose some portion of memory to the
client. Authoritative servers may crash on restart after transferring a
zone containing records with zero-length RDATA fields. These would
result in a denial of service, or leak of sensitive information.