net.resolvers.service: Understand when service is explicitly unavailable

RFC2782 states:
> A Target of "." means that the service is decidedly not available at
> this domain.

1 files changed, 5 insertions, 0 deletions

diff --git a/net/resolvers/service.lua b/net/resolvers/service.lua
index 736a838b..036317e5 100644
--- a/net/resolvers/service.lua
+++ b/net/resolvers/service.lua
@@ -34,6 +34,11 @@ function methods:next(cb)
 	local dns_resolver = adns.resolver();
 	dns_resolver:lookup(function (answer)
 		if answer then
+			if #answer == 1 and answer[1].srv.target == "." then -- No service here
+				ready();
+				return;
+			end
+
 			table.sort(answer, function (a, b) return a.priority > b.priority end);
 			for _, record in ipairs(answer) do
 				table.insert(targets, { record.srv.target, record.srv.port, self.conn_type, self.extra });