[FIXED] Cluster toplogy change possibly not sent to clients

When a server accepts a route, it will keep track of that server
`connectURLs` array. However, if the server was creating a route
to that other server at the same time, it will promote the route
as a solicited one. The content of that array was not transfered,
which means that on a disconnect, it was possible that the cluster
topology change was not properly sent to clients.

server/route.go

@@ -564,6 +564,9 @@ func (s *Server) addRoute(c *client, info *Info) (bool, bool) {
 		remote.mu.Lock()
 		// r will be not nil if c.route.didSolicit was true
 		if r != nil {
+			// If we upgrade to solicited, we still want to keep the remote's
+			// connectURLs. So transfer those.
+			r.connectURLs = remote.route.connectURLs
 			remote.route = r
 		}
 		// This is to mitigate the issue where both sides add the route

server/routes_test.go

@@ -728,3 +728,58 @@ func TestRoutesToEachOther(t *testing.T) {
 		t.Log("Was not able to get duplicate route this time!")
 	}
 }
+
+func TestConnectULRsWithRoutesToEachOther(t *testing.T) {
+	optsA := DefaultOptions()
+	optsA.Host = "127.0.0.1"
+	optsA.Cluster.Port = 7246
+	optsA.Routes = RoutesFromStr("nats://127.0.0.1:7247")
+
+	optsB := DefaultOptions()
+	optsB.Host = "127.0.0.1"
+	optsB.Cluster.Port = 7247
+	optsB.Routes = RoutesFromStr("nats://127.0.0.1:7246")
+
+	// Start servers with go routines to increase change of
+	// each server connecting to each other at the same time.
+	srvA := New(optsA)
+	defer srvA.Shutdown()
+
+	srvB := New(optsB)
+	defer srvB.Shutdown()
+
+	go srvA.Start()
+	go srvB.Start()
+
+	// Wait for cluster to be formed
+	checkClusterFormed(t, srvA, srvB)
+
+	// Connect to serverB
+	url := fmt.Sprintf("nats://%s", srvB.Addr().String())
+	nc, err := nats.Connect(url)
+	if err != nil {
+		t.Fatalf("Error on connect: %v", err)
+	}
+	defer nc.Close()
+	ds := nc.Servers()
+	if len(ds) != 2 {
+		t.Fatalf("Expected 2 servers, got %v", ds)
+	}
+
+	// Shutdown server A and make sure that we are notfied
+	// that server A is no longer running.
+	srvA.Shutdown()
+	timeout := time.Now().Add(5 * time.Second)
+	ok := false
+	for time.Now().Before(timeout) {
+		ds = nc.Servers()
+		if len(ds) == 1 {
+			ok = true
+			break
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+	if !ok {
+		t.Fatalf("List of servers should be only 1, got %v", ds)
+	}
+}

server/server.go

@@ -255,10 +255,11 @@ func (s *Server) logPid() error {
 func (s *Server) Start() {
 	s.Noticef("Starting nats-server version %s", VERSION)
 	s.Debugf("Go build version %s", s.info.GoVersion)
-	if gitCommit == "" {
-		gitCommit = "not set"
+	gc := gitCommit
+	if gc == "" {
+		gc = "not set"
 	}
-	s.Noticef("Git commit [%s]", gitCommit)
+	s.Noticef("Git commit [%s]", gc)
 
 	// Avoid RACE between Start() and Shutdown()
 	s.mu.Lock()