bug fix

src/rendezvous_server.rs

@@ -640,6 +640,17 @@ impl RendezvousServer {
                 },
             };
             let socket_addr = AddrMangle::encode(addr);
+            let relay_server = {
+                if self.relay_servers.is_empty() {
+                    "".to_owned()
+                } else {
+                    let i = unsafe {
+                        ROTATION_RELAY_SERVER += 1;
+                        ROTATION_RELAY_SERVER % self.relay_servers.len()
+                    };
+                    self.relay_servers[i].clone()
+                }
+            };
             if same_intranet {
                 log::debug!(
                     "Fetch local addr {:?} {:?} request from {:?}",
@@ -647,13 +658,9 @@ impl RendezvousServer {
                     &peer.socket_addr,
                     &addr
                 );
-                let i = unsafe {
-                    ROTATION_RELAY_SERVER += 1;
-                    ROTATION_RELAY_SERVER % self.relay_servers.len()
-                };
                 msg_out.set_fetch_local_addr(FetchLocalAddr {
                     socket_addr,
-                    relay_server: self.relay_servers[i].clone(),
+                    relay_server,
                     ..Default::default()
                 });
             } else {
@@ -663,14 +670,10 @@ impl RendezvousServer {
                     &peer.socket_addr,
                     &addr
                 );
-                let i = unsafe {
-                    ROTATION_RELAY_SERVER += 1;
-                    ROTATION_RELAY_SERVER % self.relay_servers.len()
-                };
                 msg_out.set_punch_hole(PunchHole {
                     socket_addr,
                     nat_type: ph.nat_type,
-                    relay_server: self.relay_servers[i].clone(),
+                    relay_server,
                     ..Default::default()
                 });
             }