Problem: TCP_NODELAY is set prior to connecting, which is problematic on Windows

Solution: Set TCP_NODELAY after connect()

Reference: https://mail.openvswitch.org/pipermail/ovs-dev/2014-October/290251.html

src/ip.cpp

@@ -436,9 +436,6 @@ int zmq::make_fdpair (fd_t *r_, fd_t *w_)
     *w_ = open_socket (AF_INET, SOCK_STREAM, 0);
     wsa_assert (*w_ != INVALID_SOCKET);
 
-    //  Set TCP_NODELAY on writer socket.
-    tune_socket (*w_);
-
     if (sync != NULL) {
         //  Enter the critical section.
         DWORD dwrc = WaitForSingleObject (sync, INFINITE);
@@ -465,6 +462,9 @@ int zmq::make_fdpair (fd_t *r_, fd_t *w_)
         rc = connect (*w_, reinterpret_cast<struct sockaddr *> (&addr),
                       sizeof addr);
 
+    //  Set TCP_NODELAY on writer socket.
+    tune_socket (*w_);
+
     //  Accept connection from writer.
     if (rc != SOCKET_ERROR)
         *r_ = accept (listener, NULL, NULL);