From 9a7abe68fd8fc8e7773a7a3add270210440c9e70 Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Thu, 20 Aug 2015 20:18:56 +0100
Subject: [PATCH] optimise response construction when no truncation is required

no need to do a binary search if all the answers fit
---
 nameserver/dns.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/nameserver/dns.go b/nameserver/dns.go
index a436aac6..e927cf99 100644
--- a/nameserver/dns.go
+++ b/nameserver/dns.go
@@ -246,10 +246,10 @@ func (h *handler) makeResponse(req *dns.Msg, answers []dns.RR) *dns.Msg {
 	response.SetReply(req)
 	response.RecursionAvailable = true
 	response.Authoritative = true
+	response.Answer = answers
 
 	maxSize := h.getMaxResponseSize(req)
-	if len(answers) <= 1 || maxSize <= 0 {
-		response.Answer = answers
+	if len(answers) <= 1 || maxSize <= 0 || response.Len() <= maxSize {
 		return response
 	}