From 558d47eba7d2edd3fb5991af428d9d432fec1dfa Mon Sep 17 00:00:00 2001
From: Otto <otto.moerbeek@open-xchange.com>
Date: Fri, 5 Feb 2021 16:18:55 +0100
Subject: [PATCH] Return current rcode instead of 0 if there are no CNAME
 records to follow.

Note that this is a change in behaviour. While it is for the good, it might
be existing code depends on the old 0 value...
---
 pdns/lua-recursor4.cc | 2 +-
 pdns/pdns_recursor.cc | 8 ++++----
 pdns/syncres.hh       | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/pdns/lua-recursor4.cc b/pdns/lua-recursor4.cc
index 2e742cd549..d2f57f7918 100644
--- a/pdns/lua-recursor4.cc
+++ b/pdns/lua-recursor4.cc
@@ -664,7 +664,7 @@ loop:;
     
     if(!dq.followupFunction.empty()) {
       if(dq.followupFunction=="followCNAMERecords") {
-        ret = followCNAMERecords(dq.records, QType(dq.qtype));
+        ret = followCNAMERecords(dq.records, QType(dq.qtype), ret);
       }
       else if(dq.followupFunction=="getFakeAAAARecords") {
         ret=getFakeAAAARecords(dq.followupName, ComboAddress(dq.followupPrefix), dq.records);
diff --git a/pdns/pdns_recursor.cc b/pdns/pdns_recursor.cc
index 66fc158d2f..3e4348caff 100644
--- a/pdns/pdns_recursor.cc
+++ b/pdns/pdns_recursor.cc
@@ -1352,7 +1352,7 @@ static bool udrCheckUniqueDNSRecord(const DNSName& dname, uint16_t qtype, const
 }
 #endif /* NOD_ENABLED */
 
-int followCNAMERecords(vector<DNSRecord>& ret, const QType& qtype)
+int followCNAMERecords(vector<DNSRecord>& ret, const QType& qtype, int rcode)
 {
   vector<DNSRecord> resolved;
   DNSName target;
@@ -1367,10 +1367,10 @@ int followCNAMERecords(vector<DNSRecord>& ret, const QType& qtype)
   }
 
   if(target.empty()) {
-    return 0;
+    return rcode;
   }
 
-  int rcode = directResolve(target, qtype, QClass::IN, resolved);
+  rcode = directResolve(target, qtype, QClass::IN, resolved);
 
   for(DNSRecord& rr :  resolved) {
     ret.push_back(std::move(rr));
@@ -1691,7 +1691,7 @@ static void startDoResolve(void *p)
         ret = std::move(dc->d_records);
         res = *dc->d_rcode;
         if (res == RCode::NoError && dc->d_followCNAMERecords) {
-          res = followCNAMERecords(ret, QType(dc->d_mdp.d_qtype));
+          res = followCNAMERecords(ret, QType(dc->d_mdp.d_qtype), res);
         }
         goto haveAnswer;
       }
diff --git a/pdns/syncres.hh b/pdns/syncres.hh
index 2a7c8d9d61..5bb8821ae5 100644
--- a/pdns/syncres.hh
+++ b/pdns/syncres.hh
@@ -1094,7 +1094,7 @@ void broadcastFunction(const pipefunc_t& func);
 void distributeAsyncFunction(const std::string& question, const pipefunc_t& func);
 
 int directResolve(const DNSName& qname, const QType& qtype, int qclass, vector<DNSRecord>& ret);
-int followCNAMERecords(std::vector<DNSRecord>& ret, const QType& qtype);
+int followCNAMERecords(std::vector<DNSRecord>& ret, const QType& qtype, int oldret);
 int getFakeAAAARecords(const DNSName& qname, ComboAddress prefix, vector<DNSRecord>& ret);
 int getFakePTRRecords(const DNSName& qname, vector<DNSRecord>& ret);
 
-- 
2.47.2