It appears that supernode_disconnect() might only be called in the original code in the TCP case, so add that test - even though the function appear to work in either caes

src/edge_utils.c

@@ -1063,9 +1063,19 @@ static ssize_t sendto_fd (n2n_edge_t *eee, const void *buf,
      * if the sendto had an error
      */
 err_out:
+    if(eee->conf.connect_tcp) {
         supernode_disconnect(eee);
         eee->sn_wait = 1;
         traceEvent(TRACE_DEBUG, "error in sendto_fd");
+    }
+
+    /*
+     * If we got an error and are using UDP, this is still an error
+     * case.  The only caller of sendto_fd() checks the return only
+     * in the TCP case.
+     *
+     * Thus, we can safely return an error code for any error.
+     */
     return -1;
 }