From d0f4170e3584cbb48afef82af323e722b7fb5c7f Mon Sep 17 00:00:00 2001
From: bigeagle <justin.w.xd@gmail.com>
Date: Tue, 3 Feb 2015 23:20:36 +0800
Subject: [PATCH] only cache successful lookups

---
 handler.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/handler.go b/handler.go
index 8585670..b3fd57c 100644
--- a/handler.go
+++ b/handler.go
@@ -147,7 +147,7 @@ func (h *GODNSHandler) do(Net string, w dns.ResponseWriter, req *dns.Msg) {
 
 	w.WriteMsg(mesg)
 
-	if IPQuery > 0 {
+	if IPQuery > 0 && len(mesg.Answer) > 0 {
 		err = h.cache.Set(key, mesg)
 
 		if err != nil {