dhtrunner: don't read port config if already configured

src/dhtrunner.cpp

@@ -119,25 +119,27 @@ DhtRunner::run(const Config& config, Context&& context)
         local6.setFamily(AF_INET6);
     }
     auto state_path = config.dht_config.node_config.persist_path;
-    if (not state_path.empty()) {
+    if (not state_path.empty() && (local4.getPort() == 0 || local6.getPort() == 0)) {
         state_path += "_port.txt";
         std::ifstream inConfig(state_path);
         if (inConfig.is_open()) {
             in_port_t port;
             if (inConfig >> port) {
+                if (local4.getPort() == 0) {
                     if (context.logger)
                         context.logger->d("[runner %p] Using IPv4 port %hu from saved configuration", this, port);
-                if (local4.getPort() == 0)
                     local4.setPort(port);
                 }
+            }
             if (inConfig >> port) {
+                if (local6.getPort() == 0) {
                     if (context.logger)
                         context.logger->d("[runner %p] Using IPv6 port %hu from saved configuration", this, port);
-                if (local6.getPort() == 0)
                     local6.setPort(port);
                 }
             }
         }
+    }
 
     if (not context.sock)
         context.sock.reset(new net::UdpSocket(local4, local6, context.logger));