Comment 30 for bug 578265

RFC 2782 says:

   A SRV-cognizant client SHOULD use this procedure to locate a list of
   servers and connect to the preferred one:

        Do a lookup for QNAME=_service._protocol.target, QCLASS=IN,
        QTYPE=SRV.

        If the reply is NOERROR, ANCOUNT>0 and there is at least one
        SRV RR which specifies the requested Service and Protocol in
        the reply:

            [...]

        else

            Do a lookup for QNAME=target, QCLASS=IN, QTYPE=A

So our workaround is right, but GLib probably shouldn't be failing with such a nonspecific error: it should just go for the A record itself.