Handle the root in a specific way (see issue #4)

Author: bortzmeyer

server.go

@@ -239,7 +239,11 @@ func parse(buf *bytes.Buffer) (types.DNSpacket, bool) {
 		labels[nlabels-1] = string(label)
 	}
 	packet.Qsection = make([]types.Qentry, packet.Qdcount)
-	packet.Qsection[0].Qname = strings.Join(labels, ".")
+	if len(labels) == 0 { // A special case, the root (see issue #4)
+		packet.Qsection[0].Qname = "."
+	} else {
+		packet.Qsection[0].Qname = strings.Join(labels, ".")
+	}
 	packet.Qsection[0].Qtype, ok = readShortInteger(buf)
 	if !ok {
 		return packet, false

types.go

@@ -143,7 +143,10 @@ func Encode(name string) []byte {
 	var (
 		totalresult []byte
 	)
-	labels := strings.Split(name, ".", -1)
+	labels := make([]string, 0)
+	if name != "." { // The root is a special case. See issue #4
+		labels = strings.Split(name, ".", -1)
+	}
 	totallength := 0
 	totalresult = make([]byte, 256) // TODO what a waste
 	for _, label := range labels {