This is a best effort attempt to skip connection attempts if we detect a broken
ISP resolver. A broken ISP resolver is a resolver that will replace NXDOMAIN
replies with a dummy response. This is best effort in that it'll only detect a
single fixed dummy reply, it'll check only on startup, and will not detect if we
switched networks. It should be good enough for most cases, and in the worst
case it will result in a connection attempt that does not complete.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
Reported-by: Glenn Willen <@gwillen>
4a5cff8490