Remove dns.ErrTruncated according to https://github.com/miekg/dns/pull/815

doh-client/client.go

@@ -273,7 +273,7 @@ func (c *Client) handlerFunc(w dns.ResponseWriter, r *dns.Msg, isTCP bool) {
 		} else {
 			reply, _, err = c.tcpClient.Exchange(r, upstream)
 		}
-		if err == nil || err == dns.ErrTruncated {
+		if err == nil {
 			w.WriteMsg(reply)
 			return
 		}

doh-client/ietf.go

@@ -205,7 +205,7 @@ func (c *Client) parseResponseIETF(ctx context.Context, w dns.ResponseWriter, r
 
 	fullReply := new(dns.Msg)
 	err = fullReply.Unpack(body)
-	if err != nil && err != dns.ErrTruncated {
+	if err != nil {
 		log.Println(err)
 		req.reply.Rcode = dns.RcodeServerFailure
 		w.WriteMsg(req.reply)