packer/rpc: accept/dial stream IDs are unique [GH-727]

packer/rpc/client.go

@@ -17,7 +17,7 @@ type Client struct {
 }
 
 func NewClient(rwc io.ReadWriteCloser) (*Client, error) {
-	result, err := newClientWithMux(NewMuxConn(rwc, 0), 0)
+	result, err := newClientWithMux(NewMuxConn(rwc), 0)
 	if err != nil {
 		return nil, err
 	}

packer/rpc/communicator.go

@@ -164,7 +164,7 @@ func (c *CommunicatorServer) Start(args *CommunicatorStartArgs, reply *interface
 		}
 	}()
 
-	if args.StdinStreamId > 0 {
+	if args.StdinStreamId >= 0 {
 		conn, err := c.mux.Dial(args.StdinStreamId)
 		if err != nil {
 			close(doneCh)
@@ -175,7 +175,7 @@ func (c *CommunicatorServer) Start(args *CommunicatorStartArgs, reply *interface
 		cmd.Stdin = conn
 	}
 
-	if args.StdoutStreamId > 0 {
+	if args.StdoutStreamId >= 0 {
 		conn, err := c.mux.Dial(args.StdoutStreamId)
 		if err != nil {
 			close(doneCh)
@@ -186,7 +186,7 @@ func (c *CommunicatorServer) Start(args *CommunicatorStartArgs, reply *interface
 		cmd.Stdout = conn
 	}
 
-	if args.StderrStreamId > 0 {
+	if args.StderrStreamId >= 0 {
 		conn, err := c.mux.Dial(args.StderrStreamId)
 		if err != nil {
 			close(doneCh)
@@ -253,7 +253,6 @@ func (c *CommunicatorServer) Download(args *CommunicatorDownloadArgs, reply *int
 }
 
 func serveSingleCopy(name string, mux *MuxConn, id uint32, dst io.Writer, src io.Reader) {
-	log.Printf("[DEBUG] %s: Connecting to stream %d", name, id)
 	conn, err := mux.Accept(id)
 	if err != nil {
 		log.Printf("[ERR] '%s' accept error: %s", name, err)

packer/rpc/muxconn_test.go

@@ -33,7 +33,7 @@ func testMux(t *testing.T) (client *MuxConn, server *MuxConn) {
 			t.Fatalf("err: %s", err)
 		}
 
-		server = NewMuxConn(conn, 1)
+		server = NewMuxConn(conn)
 	}()
 
 	// Client side
@@ -41,7 +41,7 @@ func testMux(t *testing.T) (client *MuxConn, server *MuxConn) {
 	if err != nil {
 		t.Fatalf("err: %s", err)
 	}
-	client = NewMuxConn(conn, 0)
+	client = NewMuxConn(conn)
 
 	// Wait for the server
 	<-doneCh
@@ -241,14 +241,14 @@ func TestMuxConnNextId(t *testing.T) {
 	a := client.NextId()
 	b := client.NextId()
 
-	if a != 0 || b != 2 {
+	if a != 0 || b != 1 {
 		t.Fatalf("IDs should increment")
 	}
 
 	a = server.NextId()
 	b = server.NextId()
 
-	if a != 1 || b != 3 {
+	if a != 0 || b != 1 {
 		t.Fatalf("IDs should increment: %d %d", a, b)
 	}
 }

packer/rpc/server.go

@@ -36,7 +36,7 @@ type Server struct {
 
 // NewServer returns a new Packer RPC server.
 func NewServer(conn io.ReadWriteCloser) *Server {
-	result := newServerWithMux(NewMuxConn(conn, 1), 0)
+	result := newServerWithMux(NewMuxConn(conn), 0)
 	result.closeMux = true
 	return result
 }