From f4e5b47dfc6633fd1af439fd22bc3634d7c6cb15 Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Wed, 15 Feb 2017 09:30:00 +0100
Subject: [PATCH] dnsdist: Don't cache ServFail / Refused if the TTL is set to
 0

---
 pdns/dnsdist-cache.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pdns/dnsdist-cache.cc b/pdns/dnsdist-cache.cc
index ec3358795..75ae261df 100644
--- a/pdns/dnsdist-cache.cc
+++ b/pdns/dnsdist-cache.cc
@@ -53,6 +53,9 @@ void DNSDistPacketCache::insert(uint32_t key, const DNSName& qname, uint16_t qty
 
   if (rcode == RCode::ServFail || rcode == RCode::Refused) {
     minTTL = d_tempFailureTTL;
+    if (minTTL == 0) {
+      return;
+    }
   }
   else {
     minTTL = getMinTTL(response, responseLen);
-- 
2.40.0