From 6ddb008aa98f9793564c1189393285374bba0f1f Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 19 Mar 2018 19:03:11 +0100
Subject: [PATCH] dnsdist: Only update the DynBlock state holders when needed

---
 pdns/dnsdist-lua.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/pdns/dnsdist-lua.cc b/pdns/dnsdist-lua.cc
index dfe31e4e05..97f589fa11 100644
--- a/pdns/dnsdist-lua.cc
+++ b/pdns/dnsdist-lua.cc
@@ -822,6 +822,9 @@ void setupLuaConfig(bool client)
 
   g_lua.writeFunction("addDynBlocks",
                       [](const std::unordered_map<ComboAddress,unsigned int, ComboAddress::addressOnlyHash, ComboAddress::addressOnlyEqual>& m, const std::string& msg, boost::optional<int> seconds, boost::optional<DNSAction::Action> action) {
+                           if (m.empty()) {
+                             return;
+                           }
                            setLuaSideEffect();
 			   auto slow = g_dynblockNMG.getCopy();
 			   struct timespec until, now;
@@ -852,6 +855,9 @@ void setupLuaConfig(bool client)
 
   g_lua.writeFunction("addDynBlockSMT",
                       [](const vector<pair<unsigned int, string> >&names, const std::string& msg, boost::optional<int> seconds, boost::optional<DNSAction::Action> action) {
+                           if (names.empty()) {
+                             return;
+                           }
                            setLuaSideEffect();
 			   auto slow = g_dynblockSMT.getCopy();
 			   struct timespec until, now;
-- 
2.47.2