libgo: update to Go 1.10.2 release

    
    Reviewed-on: https://go-review.googlesource.com/115196

From-SVN: r261041

5 files changed, 147 insertions, 32 deletions

diff --git a/libgo/go/net/http/pprof/pprof.go b/libgo/go/net/http/pprof/pprof.go
index 21992d6..77e0bcd 100644
--- a/libgo/go/net/http/pprof/pprof.go
+++ b/libgo/go/net/http/pprof/pprof.go
@@ -80,6 +80,7 @@ func init() {
 // command line, with arguments separated by NUL bytes.
 // The package initialization registers it as /debug/pprof/cmdline.
 func Cmdline(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 	fmt.Fprintf(w, strings.Join(os.Args, "\x00"))
 }
@@ -100,33 +101,36 @@ func durationExceedsWriteTimeout(r *http.Request, seconds float64) bool {
 	return ok && srv.WriteTimeout != 0 && seconds >= srv.WriteTimeout.Seconds()
 }
 
+func serveError(w http.ResponseWriter, status int, txt string) {
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.Header().Set("X-Go-Pprof", "1")
+	w.Header().Del("Content-Disposition")
+	w.WriteHeader(status)
+	fmt.Fprintln(w, txt)
+}
+
 // Profile responds with the pprof-formatted cpu profile.
 // The package initialization registers it as /debug/pprof/profile.
 func Profile(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	sec, _ := strconv.ParseInt(r.FormValue("seconds"), 10, 64)
 	if sec == 0 {
 		sec = 30
 	}
 
 	if durationExceedsWriteTimeout(r, float64(sec)) {
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusBadRequest)
-		fmt.Fprintln(w, "profile duration exceeds server's WriteTimeout")
+		serveError(w, http.StatusBadRequest, "profile duration exceeds server's WriteTimeout")
 		return
 	}
 
 	// Set Content Type assuming StartCPUProfile will work,
 	// because if it does it starts writing.
 	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Disposition", `attachment; filename="profile"`)
 	if err := pprof.StartCPUProfile(w); err != nil {
 		// StartCPUProfile failed, so no writes yet.
-		// Can change header back to text content
-		// and send error code.
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusInternalServerError)
-		fmt.Fprintf(w, "Could not enable CPU profiling: %s\n", err)
+		serveError(w, http.StatusInternalServerError,
+			fmt.Sprintf("Could not enable CPU profiling: %s", err))
 		return
 	}
 	sleep(w, time.Duration(sec)*time.Second)
@@ -137,29 +141,25 @@ func Profile(w http.ResponseWriter, r *http.Request) {
 // Tracing lasts for duration specified in seconds GET parameter, or for 1 second if not specified.
 // The package initialization registers it as /debug/pprof/trace.
 func Trace(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	sec, err := strconv.ParseFloat(r.FormValue("seconds"), 64)
 	if sec <= 0 || err != nil {
 		sec = 1
 	}
 
 	if durationExceedsWriteTimeout(r, sec) {
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusBadRequest)
-		fmt.Fprintln(w, "profile duration exceeds server's WriteTimeout")
+		serveError(w, http.StatusBadRequest, "profile duration exceeds server's WriteTimeout")
 		return
 	}
 
 	// Set Content Type assuming trace.Start will work,
 	// because if it does it starts writing.
 	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Disposition", `attachment; filename="trace"`)
 	if err := trace.Start(w); err != nil {
 		// trace.Start failed, so no writes yet.
-		// Can change header back to text content and send error code.
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusInternalServerError)
-		fmt.Fprintf(w, "Could not enable tracing: %s\n", err)
+		serveError(w, http.StatusInternalServerError,
+			fmt.Sprintf("Could not enable tracing: %s", err))
 		return
 	}
 	sleep(w, time.Duration(sec*float64(time.Second)))
@@ -170,6 +170,7 @@ func Trace(w http.ResponseWriter, r *http.Request) {
 // responding with a table mapping program counters to function names.
 // The package initialization registers it as /debug/pprof/symbol.
 func Symbol(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 
 	// We have to read the whole POST body before
@@ -222,18 +223,23 @@ func Handler(name string) http.Handler {
 type handler string
 
 func (name handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-	debug, _ := strconv.Atoi(r.FormValue("debug"))
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	p := pprof.Lookup(string(name))
 	if p == nil {
-		w.WriteHeader(404)
-		fmt.Fprintf(w, "Unknown profile: %s\n", name)
+		serveError(w, http.StatusNotFound, "Unknown profile")
 		return
 	}
 	gc, _ := strconv.Atoi(r.FormValue("gc"))
 	if name == "heap" && gc > 0 {
 		runtime.GC()
 	}
+	debug, _ := strconv.Atoi(r.FormValue("debug"))
+	if debug != 0 {
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	} else {
+		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, name))
+	}
 	p.WriteTo(w, debug)
 }
 
diff --git a/libgo/go/net/http/pprof/pprof_test.go b/libgo/go/net/http/pprof/pprof_test.go
new file mode 100644
index 0000000..47dd35b
--- /dev/null
+++ b/libgo/go/net/http/pprof/pprof_test.go
@@ -0,0 +1,69 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pprof
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHandlers(t *testing.T) {
+	testCases := []struct {
+		path               string
+		handler            http.HandlerFunc
+		statusCode         int
+		contentType        string
+		contentDisposition string
+		resp               []byte
+	}{
+		{"/debug/pprof/<script>scripty<script>", Index, http.StatusNotFound, "text/plain; charset=utf-8", "", []byte("Unknown profile\n")},
+		{"/debug/pprof/heap", Index, http.StatusOK, "application/octet-stream", `attachment; filename="heap"`, nil},
+		{"/debug/pprof/heap?debug=1", Index, http.StatusOK, "text/plain; charset=utf-8", "", nil},
+		{"/debug/pprof/cmdline", Cmdline, http.StatusOK, "text/plain; charset=utf-8", "", nil},
+		{"/debug/pprof/profile?seconds=1", Profile, http.StatusOK, "application/octet-stream", `attachment; filename="profile"`, nil},
+		{"/debug/pprof/symbol", Symbol, http.StatusOK, "text/plain; charset=utf-8", "", nil},
+		{"/debug/pprof/trace", Trace, http.StatusOK, "application/octet-stream", `attachment; filename="trace"`, nil},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.path, func(t *testing.T) {
+			req := httptest.NewRequest("GET", "http://example.com"+tc.path, nil)
+			w := httptest.NewRecorder()
+			tc.handler(w, req)
+
+			resp := w.Result()
+			if got, want := resp.StatusCode, tc.statusCode; got != want {
+				t.Errorf("status code: got %d; want %d", got, want)
+			}
+
+			body, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				t.Errorf("when reading response body, expected non-nil err; got %v", err)
+			}
+			if got, want := resp.Header.Get("X-Content-Type-Options"), "nosniff"; got != want {
+				t.Errorf("X-Content-Type-Options: got %q; want %q", got, want)
+			}
+			if got, want := resp.Header.Get("Content-Type"), tc.contentType; got != want {
+				t.Errorf("Content-Type: got %q; want %q", got, want)
+			}
+			if got, want := resp.Header.Get("Content-Disposition"), tc.contentDisposition; got != want {
+				t.Errorf("Content-Disposition: got %q; want %q", got, want)
+			}
+
+			if resp.StatusCode == http.StatusOK {
+				return
+			}
+			if got, want := resp.Header.Get("X-Go-Pprof"), "1"; got != want {
+				t.Errorf("X-Go-Pprof: got %q; want %q", got, want)
+			}
+			if !bytes.Equal(body, tc.resp) {
+				t.Errorf("response: got %q; want %q", body, tc.resp)
+			}
+		})
+	}
+
+}
diff --git a/libgo/go/net/lookup.go b/libgo/go/net/lookup.go
index 85e4729..a65b735 100644
--- a/libgo/go/net/lookup.go
+++ b/libgo/go/net/lookup.go
@@ -194,10 +194,16 @@ func (r *Resolver) LookupIPAddr(ctx context.Context, host string) ([]IPAddr, err
 		resolverFunc = alt
 	}
 
+	// We don't want a cancelation of ctx to affect the
+	// lookupGroup operation. Otherwise if our context gets
+	// canceled it might cause an error to be returned to a lookup
+	// using a completely different context.
+	lookupGroupCtx, lookupGroupCancel := context.WithCancel(context.Background())
+
 	dnsWaitGroup.Add(1)
 	ch, called := lookupGroup.DoChan(host, func() (interface{}, error) {
 		defer dnsWaitGroup.Done()
-		return testHookLookupIP(ctx, resolverFunc, host)
+		return testHookLookupIP(lookupGroupCtx, resolverFunc, host)
 	})
 	if !called {
 		dnsWaitGroup.Done()
@@ -205,20 +211,28 @@ func (r *Resolver) LookupIPAddr(ctx context.Context, host string) ([]IPAddr, err
 
 	select {
 	case <-ctx.Done():
-		// If the DNS lookup timed out for some reason, force
-		// future requests to start the DNS lookup again
-		// rather than waiting for the current lookup to
-		// complete. See issue 8602.
-		ctxErr := ctx.Err()
-		if ctxErr == context.DeadlineExceeded {
-			lookupGroup.Forget(host)
+		// Our context was canceled. If we are the only
+		// goroutine looking up this key, then drop the key
+		// from the lookupGroup and cancel the lookup.
+		// If there are other goroutines looking up this key,
+		// let the lookup continue uncanceled, and let later
+		// lookups with the same key share the result.
+		// See issues 8602, 20703, 22724.
+		if lookupGroup.ForgetUnshared(host) {
+			lookupGroupCancel()
+		} else {
+			go func() {
+				<-ch
+				lookupGroupCancel()
+			}()
 		}
-		err := mapErr(ctxErr)
+		err := mapErr(ctx.Err())
 		if trace != nil && trace.DNSDone != nil {
 			trace.DNSDone(nil, false, err)
 		}
 		return nil, err
 	case r := <-ch:
+		lookupGroupCancel()
 		if trace != nil && trace.DNSDone != nil {
 			addrs, _ := r.Val.([]IPAddr)
 			trace.DNSDone(ipAddrsEface(addrs), r.Shared, r.Err)
diff --git a/libgo/go/net/lookup_test.go b/libgo/go/net/lookup_test.go
index bfb8725..24787cc 100644
--- a/libgo/go/net/lookup_test.go
+++ b/libgo/go/net/lookup_test.go
@@ -791,3 +791,28 @@ func TestLookupNonLDH(t *testing.T) {
 		t.Fatalf("lookup error = %v, want %v", err, errNoSuchHost)
 	}
 }
+
+func TestLookupContextCancel(t *testing.T) {
+	if testenv.Builder() == "" {
+		testenv.MustHaveExternalNetwork(t)
+	}
+	if runtime.GOOS == "nacl" {
+		t.Skip("skip on nacl")
+	}
+
+	defer dnsWaitGroup.Wait()
+
+	ctx, ctxCancel := context.WithCancel(context.Background())
+	ctxCancel()
+	_, err := DefaultResolver.LookupIPAddr(ctx, "google.com")
+	if err != errCanceled {
+		testenv.SkipFlakyNet(t)
+		t.Fatal(err)
+	}
+	ctx = context.Background()
+	_, err = DefaultResolver.LookupIPAddr(ctx, "google.com")
+	if err != nil {
+		testenv.SkipFlakyNet(t)
+		t.Fatal(err)
+	}
+}
diff --git a/libgo/go/net/tcpsock_unix_test.go b/libgo/go/net/tcpsock_unix_test.go
index 3af1834..95c02d2 100644
--- a/libgo/go/net/tcpsock_unix_test.go
+++ b/libgo/go/net/tcpsock_unix_test.go
@@ -87,6 +87,7 @@ func TestTCPSpuriousConnSetupCompletionWithCancel(t *testing.T) {
 	if testenv.Builder() == "" {
 		testenv.MustHaveExternalNetwork(t)
 	}
+	defer dnsWaitGroup.Wait()
 	t.Parallel()
 	const tries = 10000
 	var wg sync.WaitGroup