From 3104ff998c521fb873ff5e0b8eb12c2bf280f0f8 Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Wed, 22 Jul 2015 18:49:19 -0700
Subject: [PATCH 1/6] to be deleted

---
 credentials/credentials.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/credentials/credentials.go b/credentials/credentials.go
index 63c42a29..f8e5d354 100644
--- a/credentials/credentials.go
+++ b/credentials/credentials.go
@@ -201,12 +201,12 @@ func NewServerTLSFromFile(certFile, keyFile string) (TransportAuthenticator, err
 }
 
 // TokenSource supplies credentials from an oauth2.TokenSource.
-type TokenSource struct {
+type tokenSource struct {
 	oauth2.TokenSource
 }
 
 // GetRequestMetadata gets the request metadata as a map from a TokenSource.
-func (ts TokenSource) GetRequestMetadata(ctx context.Context) (map[string]string, error) {
+func (ts tokenSource) GetRequestMetadata(ctx context.Context) (map[string]string, error) {
 	token, err := ts.Token()
 	if err != nil {
 		return nil, err
@@ -221,7 +221,7 @@ func (ts TokenSource) GetRequestMetadata(ctx context.Context) (map[string]string
 // if your program is running on a GCE instance.
 // TODO(dsymonds): Deprecate and remove this.
 func NewComputeEngine() Credentials {
-	return TokenSource{google.ComputeTokenSource("")}
+	return tokenSource{google.ComputeTokenSource("")}
 }
 
 // serviceAccount represents credentials via JWT signing key.
@@ -266,5 +266,5 @@ func NewApplicationDefault(ctx context.Context, scope ...string) (Credentials, e
 	if err != nil {
 		return nil, err
 	}
-	return TokenSource{t}, nil
+	return tokenSource{t}, nil
 }

From e1fea116b7d06bb2ddcb35ec52bb0a22378dc697 Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Wed, 22 Jul 2015 19:24:44 -0700
Subject: [PATCH 2/6] revert

---
 credentials/credentials.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/credentials/credentials.go b/credentials/credentials.go
index f8e5d354..63c42a29 100644
--- a/credentials/credentials.go
+++ b/credentials/credentials.go
@@ -201,12 +201,12 @@ func NewServerTLSFromFile(certFile, keyFile string) (TransportAuthenticator, err
 }
 
 // TokenSource supplies credentials from an oauth2.TokenSource.
-type tokenSource struct {
+type TokenSource struct {
 	oauth2.TokenSource
 }
 
 // GetRequestMetadata gets the request metadata as a map from a TokenSource.
-func (ts tokenSource) GetRequestMetadata(ctx context.Context) (map[string]string, error) {
+func (ts TokenSource) GetRequestMetadata(ctx context.Context) (map[string]string, error) {
 	token, err := ts.Token()
 	if err != nil {
 		return nil, err
@@ -221,7 +221,7 @@ func (ts tokenSource) GetRequestMetadata(ctx context.Context) (map[string]string
 // if your program is running on a GCE instance.
 // TODO(dsymonds): Deprecate and remove this.
 func NewComputeEngine() Credentials {
-	return tokenSource{google.ComputeTokenSource("")}
+	return TokenSource{google.ComputeTokenSource("")}
 }
 
 // serviceAccount represents credentials via JWT signing key.
@@ -266,5 +266,5 @@ func NewApplicationDefault(ctx context.Context, scope ...string) (Credentials, e
 	if err != nil {
 		return nil, err
 	}
-	return tokenSource{t}, nil
+	return TokenSource{t}, nil
 }

From 611d9607577a3d4245bc0070698338ede17bc4e6 Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Fri, 24 Jul 2015 11:19:08 -0700
Subject: [PATCH 3/6] support user-agent and allow users attach their own
 application user agent string

---
 clientconn.go             |  9 ++++--
 test/end2end_test.go      | 66 ++++++++++++++++++++++-----------------
 transport/http2_client.go |  8 +++++
 transport/http_util.go    | 15 +++++++--
 transport/transport.go    |  5 +++
 5 files changed, 71 insertions(+), 32 deletions(-)

diff --git a/clientconn.go b/clientconn.go
index e7bb9453..bc6d6f5b 100644
--- a/clientconn.go
+++ b/clientconn.go
@@ -114,9 +114,14 @@ func WithDialer(f func(addr string, timeout time.Duration) (net.Conn, error)) Di
 	}
 }
 
+// WithUserAgent returns a DialOption that specifies a user agent string for all the RPCs.
+func WithUserAgent(s string) DialOption {
+	return func(o *dialOptions) {
+		o.copts.UserAgent = s
+	}
+}
+
 // Dial creates a client connection the given target.
-// TODO(zhaoq): Have an option to make Dial return immediately without waiting
-// for connection to complete.
 func Dial(target string, opts ...DialOption) (*ClientConn, error) {
 	if target == "" {
 		return nil, ErrUnspecTarget
diff --git a/test/end2end_test.go b/test/end2end_test.go
index 8430ed28..9b541e6e 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -62,15 +62,21 @@ var (
 		"key1": "value1",
 		"key2": "value2",
 	}
+	testAppUA = "myApp/1.0"
 )
 
 type testServer struct {
 }
 
 func (s *testServer) EmptyCall(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) {
-	if _, ok := metadata.FromContext(ctx); ok {
-		// For testing purpose, returns an error if there is attached metadata.
-		return nil, grpc.Errorf(codes.DataLoss, "got extra metadata")
+	if md, ok := metadata.FromContext(ctx); ok {
+		// For testing purpose, returns an error if there is attached metadata other than
+		// the user agent set by the client application.
+		if ua, isOK := md["user-agent"]; isOK {
+			grpc.SendHeader(ctx, metadata.Pairs("ua", ua))
+		} else {
+			return nil, grpc.Errorf(codes.DataLoss, "got extra metadata")
+		}
 	}
 	return new(testpb.Empty), nil
 }
@@ -285,7 +291,7 @@ func listTestEnv() []env {
 	return []env{env{"tcp", nil, ""}, env{"tcp", nil, "tls"}, env{"unix", unixDialer, ""}, env{"unix", unixDialer, "tls"}}
 }
 
-func setUp(hs *health.HealthServer, maxStream uint32, e env) (s *grpc.Server, cc *grpc.ClientConn) {
+func setUp(hs *health.HealthServer, maxStream uint32, ua string, e env) (s *grpc.Server, cc *grpc.ClientConn) {
 	sopts := []grpc.ServerOption{grpc.MaxConcurrentStreams(maxStream)}
 	la := ":0"
 	switch e.network {
@@ -325,9 +331,9 @@ func setUp(hs *health.HealthServer, maxStream uint32, e env) (s *grpc.Server, cc
 		if err != nil {
 			grpclog.Fatalf("Failed to create credentials %v", err)
 		}
-		cc, err = grpc.Dial(addr, grpc.WithTransportCredentials(creds), grpc.WithDialer(e.dialer))
+		cc, err = grpc.Dial(addr, grpc.WithTransportCredentials(creds), grpc.WithDialer(e.dialer), grpc.WithUserAgent(ua))
 	} else {
-		cc, err = grpc.Dial(addr, grpc.WithDialer(e.dialer))
+		cc, err = grpc.Dial(addr, grpc.WithDialer(e.dialer), grpc.WithUserAgent(ua))
 	}
 	if err != nil {
 		grpclog.Fatalf("Dial(%q) = %v", addr, err)
@@ -347,7 +353,7 @@ func TestTimeoutOnDeadServer(t *testing.T) {
 }
 
 func testTimeoutOnDeadServer(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	s.Stop()
 	// Set -1 as the timeout to make sure if transportMonitor gets error
@@ -379,7 +385,7 @@ func TestHealthCheckOnSuccess(t *testing.T) {
 func testHealthCheckOnSuccess(t *testing.T, e env) {
 	hs := health.NewHealthServer()
 	hs.SetServingStatus("", "grpc.health.v1alpha.HealthCheck", 1)
-	s, cc := setUp(hs, math.MaxUint32, e)
+	s, cc := setUp(hs, math.MaxUint32, "", e)
 	defer tearDown(s, cc)
 	if _, err := healthCheck(1*time.Second, cc, "grpc.health.v1alpha.HealthCheck"); err != nil {
 		t.Fatalf("HealthCheck/Check(_, _) = _, %v, want _, <nil>", err)
@@ -395,7 +401,7 @@ func TestHealthCheckOnFailure(t *testing.T) {
 func testHealthCheckOnFailure(t *testing.T, e env) {
 	hs := health.NewHealthServer()
 	hs.SetServingStatus("", "grpc.health.v1alpha.HealthCheck", 1)
-	s, cc := setUp(hs, math.MaxUint32, e)
+	s, cc := setUp(hs, math.MaxUint32, "", e)
 	defer tearDown(s, cc)
 	if _, err := healthCheck(0*time.Second, cc, "grpc.health.v1alpha.HealthCheck"); err != grpc.Errorf(codes.DeadlineExceeded, "context deadline exceeded") {
 		t.Fatalf("HealthCheck/Check(_, _) = _, %v, want _, error code %d", err, codes.DeadlineExceeded)
@@ -409,7 +415,7 @@ func TestHealthCheckOff(t *testing.T) {
 }
 
 func testHealthCheckOff(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	defer tearDown(s, cc)
 	if _, err := healthCheck(1*time.Second, cc, ""); err != grpc.Errorf(codes.Unimplemented, "unknown service grpc.health.v1alpha.HealthCheck") {
 		t.Fatalf("HealthCheck/Check(_, _) = _, %v, want _, error code %d", err, codes.Unimplemented)
@@ -424,7 +430,7 @@ func TestHealthCheckServingStatus(t *testing.T) {
 
 func testHealthCheckServingStatus(t *testing.T, e env) {
 	hs := health.NewHealthServer()
-	s, cc := setUp(hs, math.MaxUint32, e)
+	s, cc := setUp(hs, math.MaxUint32, "", e)
 	defer tearDown(s, cc)
 	if _, err := healthCheck(1*time.Second, cc, "grpc.health.v1alpha.HealthCheck"); err != grpc.Errorf(codes.NotFound, "unknown service") {
 		t.Fatalf("HealthCheck/Check(_, _) = _, %v, want _, error code %d", err, codes.NotFound)
@@ -448,20 +454,24 @@ func testHealthCheckServingStatus(t *testing.T, e env) {
 
 }
 
-func TestEmptyUnary(t *testing.T) {
+func TestEmptyUnaryWithUserAgent(t *testing.T) {
 	for _, e := range listTestEnv() {
-		testEmptyUnary(t, e)
+		testEmptyUnaryWithUserAgent(t, e)
 	}
 }
 
-func testEmptyUnary(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+func testEmptyUnaryWithUserAgent(t *testing.T, e env) {
+	s, cc := setUp(nil, math.MaxUint32, testAppUA, e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
-	reply, err := tc.EmptyCall(context.Background(), &testpb.Empty{})
+	var header metadata.MD
+	reply, err := tc.EmptyCall(context.Background(), &testpb.Empty{}, grpc.Header(&header))
 	if err != nil || !proto.Equal(&testpb.Empty{}, reply) {
 		t.Fatalf("TestService/EmptyCall(_, _) = %v, %v, want %v, <nil>", reply, err, &testpb.Empty{})
 	}
+	if v, ok := header["ua"]; !ok || v != testAppUA {
+		t.Fatalf("header[\"ua\"] = %q, %t, want %q, true", v, ok, testAppUA)
+	}
 }
 
 func TestFailedEmptyUnary(t *testing.T) {
@@ -471,7 +481,7 @@ func TestFailedEmptyUnary(t *testing.T) {
 }
 
 func testFailedEmptyUnary(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	ctx := metadata.NewContext(context.Background(), testMetadata)
@@ -487,7 +497,7 @@ func TestLargeUnary(t *testing.T) {
 }
 
 func testLargeUnary(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	argSize := 271828
@@ -515,7 +525,7 @@ func TestMetadataUnaryRPC(t *testing.T) {
 }
 
 func testMetadataUnaryRPC(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	argSize := 2718
@@ -569,7 +579,7 @@ func TestRetry(t *testing.T) {
 // TODO(zhaoq): Refactor to make this clearer and add more cases to test racy
 // and error-prone paths.
 func testRetry(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	var wg sync.WaitGroup
@@ -599,7 +609,7 @@ func TestRPCTimeout(t *testing.T) {
 
 // TODO(zhaoq): Have a better test coverage of timeout and cancellation mechanism.
 func testRPCTimeout(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	argSize := 2718
@@ -625,7 +635,7 @@ func TestCancel(t *testing.T) {
 }
 
 func testCancel(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	argSize := 2718
@@ -657,7 +667,7 @@ func TestPingPong(t *testing.T) {
 }
 
 func testPingPong(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	stream, err := tc.FullDuplexCall(context.Background())
@@ -708,7 +718,7 @@ func TestMetadataStreamingRPC(t *testing.T) {
 }
 
 func testMetadataStreamingRPC(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	ctx := metadata.NewContext(context.Background(), testMetadata)
@@ -765,7 +775,7 @@ func TestServerStreaming(t *testing.T) {
 }
 
 func testServerStreaming(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	respParam := make([]*testpb.ResponseParameters, len(respSizes))
@@ -817,7 +827,7 @@ func TestFailedServerStreaming(t *testing.T) {
 }
 
 func testFailedServerStreaming(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	respParam := make([]*testpb.ResponseParameters, len(respSizes))
@@ -847,7 +857,7 @@ func TestClientStreaming(t *testing.T) {
 }
 
 func testClientStreaming(t *testing.T, e env) {
-	s, cc := setUp(nil, math.MaxUint32, e)
+	s, cc := setUp(nil, math.MaxUint32, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	stream, err := tc.StreamingInputCall(context.Background())
@@ -882,7 +892,7 @@ func TestExceedMaxStreamsLimit(t *testing.T) {
 
 func testExceedMaxStreamsLimit(t *testing.T, e env) {
 	// Only allows 1 live stream per server transport.
-	s, cc := setUp(nil, 1, e)
+	s, cc := setUp(nil, 1, "", e)
 	tc := testpb.NewTestServiceClient(cc)
 	defer tearDown(s, cc)
 	// Perform a unary RPC to make sure the new settings were propagated to the client.
diff --git a/transport/http2_client.go b/transport/http2_client.go
index 59f4d5c3..b5a97d33 100644
--- a/transport/http2_client.go
+++ b/transport/http2_client.go
@@ -54,6 +54,7 @@ import (
 // http2Client implements the ClientTransport interface with HTTP2.
 type http2Client struct {
 	target string   // server name/addr
+	userAgent string
 	conn   net.Conn // underlying communication channel
 	nextID uint32   // the next stream ID to be used
 
@@ -158,9 +159,14 @@ func newHTTP2Client(addr string, opts *ConnectOptions) (_ ClientTransport, err e
 			return nil, ConnectionErrorf("transport: %v", err)
 		}
 	}
+	ua := primaryUA
+	if opts.UserAgent != "" {
+		ua += " " + opts.UserAgent
+	}
 	var buf bytes.Buffer
 	t := &http2Client{
 		target: addr,
+		userAgent: ua,
 		conn:   conn,
 		// The client initiated stream id is odd starting from 1.
 		nextID:          1,
@@ -273,7 +279,9 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 	t.hEnc.WriteField(hpack.HeaderField{Name: ":path", Value: callHdr.Method})
 	t.hEnc.WriteField(hpack.HeaderField{Name: ":authority", Value: callHdr.Host})
 	t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"})
+	t.hEnc.WriteField(hpack.HeaderField{Name: "user-agent", Value: t.userAgent})
 	t.hEnc.WriteField(hpack.HeaderField{Name: "te", Value: "trailers"})
+
 	if timeout > 0 {
 		t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-timeout", Value: timeoutEncode(timeout)})
 	}
diff --git a/transport/http_util.go b/transport/http_util.go
index 2babe729..fa0a4d0c 100644
--- a/transport/http_util.go
+++ b/transport/http_util.go
@@ -39,6 +39,7 @@ import (
 	"io"
 	"net"
 	"strconv"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -50,6 +51,8 @@ import (
 )
 
 const (
+	// The primary user agent
+	primaryUA = "grpc-go/0.7"
 	// http2MaxFrameLen specifies the max length of a HTTP2 frame.
 	http2MaxFrameLen = 16384 // 16KB frame
 	// http://http2.github.io/http2-spec/#SettingValues
@@ -128,8 +131,7 @@ func isReservedHeader(hdr string) bool {
 		"grpc-message",
 		"grpc-status",
 		"grpc-timeout",
-		"te",
-		"user-agent":
+		"te":
 		return true
 	default:
 		return false
@@ -161,6 +163,15 @@ func newHPACKDecoder() *hpackDecoder {
 			d.state.method = f.Value
 		default:
 			if !isReservedHeader(f.Name) {
+				if f.Name == "user-agent" {
+					str := strings.Split(f.Value, " ")
+					if len(str) <= 1 {
+						// There is no application user agent string being set.
+						return
+					}
+					// Extract the application user agent string.
+					f.Value = str[1]
+				}
 				if d.state.mdata == nil {
 					d.state.mdata = make(map[string]string)
 				}
diff --git a/transport/transport.go b/transport/transport.go
index 498cee54..b79cfd89 100644
--- a/transport/transport.go
+++ b/transport/transport.go
@@ -320,8 +320,13 @@ func NewServerTransport(protocol string, conn net.Conn, maxStreams uint32) (Serv
 
 // ConnectOptions covers all relevant options for dialing a server.
 type ConnectOptions struct {
+	// UserAgent is the application user agent.
+	UserAgent   string
+	// Dialer specifies how to dial a network address.
 	Dialer      func(string, time.Duration) (net.Conn, error)
+	// AuthOptions stores the credentials required to setup a client connection and issue RPCs.
 	AuthOptions []credentials.Credentials
+	// Timeout specifies the timeout for dialing a client connection.
 	Timeout     time.Duration
 }
 

From 23c960bc018d1f8e0ed0c8274745245deb0b5e1b Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Fri, 24 Jul 2015 11:26:21 -0700
Subject: [PATCH 4/6] gofmt -w

---
 transport/http2_client.go | 10 +++++-----
 transport/transport.go    |  6 +++---
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/transport/http2_client.go b/transport/http2_client.go
index b5a97d33..8f79ad96 100644
--- a/transport/http2_client.go
+++ b/transport/http2_client.go
@@ -53,10 +53,10 @@ import (
 
 // http2Client implements the ClientTransport interface with HTTP2.
 type http2Client struct {
-	target string   // server name/addr
+	target    string // server name/addr
 	userAgent string
-	conn   net.Conn // underlying communication channel
-	nextID uint32   // the next stream ID to be used
+	conn      net.Conn // underlying communication channel
+	nextID    uint32   // the next stream ID to be used
 
 	// writableChan synchronizes write access to the transport.
 	// A writer acquires the write lock by sending a value on writableChan
@@ -165,9 +165,9 @@ func newHTTP2Client(addr string, opts *ConnectOptions) (_ ClientTransport, err e
 	}
 	var buf bytes.Buffer
 	t := &http2Client{
-		target: addr,
+		target:    addr,
 		userAgent: ua,
-		conn:   conn,
+		conn:      conn,
 		// The client initiated stream id is odd starting from 1.
 		nextID:          1,
 		writableChan:    make(chan int, 1),
diff --git a/transport/transport.go b/transport/transport.go
index b79cfd89..454511f7 100644
--- a/transport/transport.go
+++ b/transport/transport.go
@@ -321,13 +321,13 @@ func NewServerTransport(protocol string, conn net.Conn, maxStreams uint32) (Serv
 // ConnectOptions covers all relevant options for dialing a server.
 type ConnectOptions struct {
 	// UserAgent is the application user agent.
-	UserAgent   string
+	UserAgent string
 	// Dialer specifies how to dial a network address.
-	Dialer      func(string, time.Duration) (net.Conn, error)
+	Dialer func(string, time.Duration) (net.Conn, error)
 	// AuthOptions stores the credentials required to setup a client connection and issue RPCs.
 	AuthOptions []credentials.Credentials
 	// Timeout specifies the timeout for dialing a client connection.
-	Timeout     time.Duration
+	Timeout time.Duration
 }
 
 // NewClientTransport establishes the transport with the required ConnectOptions

From 8969f785ebbc14c96aa33a436801464083cb87a3 Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Fri, 24 Jul 2015 11:29:32 -0700
Subject: [PATCH 5/6] fix a comment

---
 transport/transport.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/transport/transport.go b/transport/transport.go
index 454511f7..c2ac3f88 100644
--- a/transport/transport.go
+++ b/transport/transport.go
@@ -324,7 +324,7 @@ type ConnectOptions struct {
 	UserAgent string
 	// Dialer specifies how to dial a network address.
 	Dialer func(string, time.Duration) (net.Conn, error)
-	// AuthOptions stores the credentials required to setup a client connection and issue RPCs.
+	// AuthOptions stores the credentials required to setup a client connection and/or issue RPCs.
 	AuthOptions []credentials.Credentials
 	// Timeout specifies the timeout for dialing a client connection.
 	Timeout time.Duration

From c33d1609af3d698e1855a441b7230d08e2715be1 Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Fri, 24 Jul 2015 11:39:27 -0700
Subject: [PATCH 6/6] refactor a bit

---
 test/end2end_test.go | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/test/end2end_test.go b/test/end2end_test.go
index 9b541e6e..8d7eac83 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -72,11 +72,10 @@ func (s *testServer) EmptyCall(ctx context.Context, in *testpb.Empty) (*testpb.E
 	if md, ok := metadata.FromContext(ctx); ok {
 		// For testing purpose, returns an error if there is attached metadata other than
 		// the user agent set by the client application.
-		if ua, isOK := md["user-agent"]; isOK {
-			grpc.SendHeader(ctx, metadata.Pairs("ua", ua))
-		} else {
+		if _, ok := md["user-agent"]; !ok {
 			return nil, grpc.Errorf(codes.DataLoss, "got extra metadata")
 		}
+		grpc.SendHeader(ctx, metadata.Pairs("ua", md["user-agent"]))
 	}
 	return new(testpb.Empty), nil
 }