Don't treat NODE_WITNESS as relevant before a fork is defined

Author: sipa

src/init.cpp

@@ -1391,6 +1391,9 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         // Note that setting NODE_WITNESS is never required: the only downside from not
         // doing so is that after activation, no upgraded nodes will fetch from you.
         nLocalServices |= NODE_WITNESS;
+        // Only care about others providing witness capabilities if there is a softfork
+        // defined.
+        nRelevantServices |= NODE_WITNESS;
     }
 
     // ********************************************************* Step 10: import blocks

src/net.cpp

@@ -72,7 +72,7 @@ namespace {
 const static std::string NET_MESSAGE_COMMAND_OTHER = "*other*";
 
 /** Services this node implementation cares about */
-static const uint64_t nRelevantServices = NODE_NETWORK | NODE_WITNESS;
+uint64_t nRelevantServices = NODE_NETWORK;
 
 //
 // Global state variables
@@ -1601,8 +1601,8 @@ void ThreadOpenConnections()
             if (nANow - addr.nLastTry < 600 && nTries < 30)
                 continue;
 
-            // only consider non-witness nodes after 40 failed attemps
-            if (!(addr.nServices & NODE_WITNESS) && nTries < 40)
+            // only consider nodes missing relevant services after 40 failed attemps
+            if ((addr.nServices & nRelevantServices) != nRelevantServices && nTries < 40)
                 continue;
 
             // do not allow non-default ports, unless after 50 invalid addresses selected already

src/net.h

@@ -153,6 +153,7 @@ CAddress GetLocalAddress(const CNetAddr *paddrPeer = NULL);
 extern bool fDiscover;
 extern bool fListen;
 extern uint64_t nLocalServices;
+extern uint64_t nRelevantServices;
 extern uint64_t nLocalHostNonce;
 extern CAddrMan addrman;