If you ask ares_gethostbyname() to do an AF_INET6 lookup and the target
host has only A records, it automatically falls back to an AF_INET
lookup and gives you the A results. However, if the target host has a
CNAME record, this behaviour is defeated since the original query does
return some data even though ares_parse_aaa_reply() doesn't consider it
relevant.
Here's a small patch to make it behave the same with and without the
CNAME.
p.