/third_party/gofrontend/libgo/go/net/http/serve_test.go

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// Copyright 2010 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.

// End-to-end serving tests

package http_test

import (
	"bufio"
	"bytes"
	"crypto/tls"
	"errors"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"math/rand"
	"net"
	. "net/http"
	"net/http/httptest"
	"net/http/httputil"
	"net/http/internal"
	"net/url"
	"os"
	"os/exec"
	"reflect"
	"runtime"
	"strconv"
	"strings"
	"sync"
	"sync/atomic"
	"syscall"
	"testing"
	"time"
)

type dummyAddr string
type oneConnListener struct {
	conn net.Conn
}

func (l *oneConnListener) Accept() (c net.Conn, err error) {
	c = l.conn
	if c == nil {
		err = io.EOF
		return
	}
	err = nil
	l.conn = nil
	return
}

func (l *oneConnListener) Close() error {
	return nil
}

func (l *oneConnListener) Addr() net.Addr {
	return dummyAddr("test-address")
}

func (a dummyAddr) Network() string {
	return string(a)
}

func (a dummyAddr) String() string {
	return string(a)
}

type noopConn struct{}

func (noopConn) LocalAddr() net.Addr                { return dummyAddr("local-addr") }
func (noopConn) RemoteAddr() net.Addr               { return dummyAddr("remote-addr") }
func (noopConn) SetDeadline(t time.Time) error      { return nil }
func (noopConn) SetReadDeadline(t time.Time) error  { return nil }
func (noopConn) SetWriteDeadline(t time.Time) error { return nil }

type rwTestConn struct {
	io.Reader
	io.Writer
	noopConn

	closeFunc func() error // called if non-nil
	closec    chan bool    // else, if non-nil, send value to it on close
}

func (c *rwTestConn) Close() error {
	if c.closeFunc != nil {
		return c.closeFunc()
	}
	select {
	case c.closec <- true:
	default:
	}
	return nil
}

type testConn struct {
	readBuf  bytes.Buffer
	writeBuf bytes.Buffer
	closec   chan bool // if non-nil, send value to it on close
	noopConn
}

func (c *testConn) Read(b []byte) (int, error) {
	return c.readBuf.Read(b)
}

func (c *testConn) Write(b []byte) (int, error) {
	return c.writeBuf.Write(b)
}

func (c *testConn) Close() error {
	select {
	case c.closec <- true:
	default:
	}
	return nil
}

// reqBytes treats req as a request (with \n delimiters) and returns it with \r\n delimiters,
// ending in \r\n\r\n
func reqBytes(req string) []byte {
	return []byte(strings.Replace(strings.TrimSpace(req), "\n", "\r\n", -1) + "\r\n\r\n")
}

type handlerTest struct {
	handler Handler
}

func newHandlerTest(h Handler) handlerTest {
	return handlerTest{h}
}

func (ht handlerTest) rawResponse(req string) string {
	reqb := reqBytes(req)
	var output bytes.Buffer
	conn := &rwTestConn{
		Reader: bytes.NewReader(reqb),
		Writer: &output,
		closec: make(chan bool, 1),
	}
	ln := &oneConnListener{conn: conn}
	go Serve(ln, ht.handler)
	<-conn.closec
	return output.String()
}

func TestConsumingBodyOnNextConn(t *testing.T) {
	defer afterTest(t)
	conn := new(testConn)
	for i := 0; i < 2; i++ {
		conn.readBuf.Write([]byte(
			"POST / HTTP/1.1\r\n" +
				"Host: test\r\n" +
				"Content-Length: 11\r\n" +
				"\r\n" +
				"foo=1&bar=1"))
	}

	reqNum := 0
	ch := make(chan *Request)
	servech := make(chan error)
	listener := &oneConnListener{conn}
	handler := func(res ResponseWriter, req *Request) {
		reqNum++
		ch <- req
	}

	go func() {
		servech <- Serve(listener, HandlerFunc(handler))
	}()

	var req *Request
	req = <-ch
	if req == nil {
		t.Fatal("Got nil first request.")
	}
	if req.Method != "POST" {
		t.Errorf("For request #1's method, got %q; expected %q",
			req.Method, "POST")
	}

	req = <-ch
	if req == nil {
		t.Fatal("Got nil first request.")
	}
	if req.Method != "POST" {
		t.Errorf("For request #2's method, got %q; expected %q",
			req.Method, "POST")
	}

	if serveerr := <-servech; serveerr != io.EOF {
		t.Errorf("Serve returned %q; expected EOF", serveerr)
	}
}

type stringHandler string

func (s stringHandler) ServeHTTP(w ResponseWriter, r *Request) {
	w.Header().Set("Result", string(s))
}

var handlers = []struct {
	pattern string
	msg     string
}{
	{"/", "Default"},
	{"/someDir/", "someDir"},
	{"/#/", "hash"},
	{"someHost.com/someDir/", "someHost.com/someDir"},
}

var vtests = []struct {
	url      string
	expected string
}{
	{"http://localhost/someDir/apage", "someDir"},
	{"http://localhost/%23/apage", "hash"},
	{"http://localhost/otherDir/apage", "Default"},
	{"http://someHost.com/someDir/apage", "someHost.com/someDir"},
	{"http://otherHost.com/someDir/apage", "someDir"},
	{"http://otherHost.com/aDir/apage", "Default"},
	// redirections for trees
	{"http://localhost/someDir", "/someDir/"},
	{"http://localhost/%23", "/%23/"},
	{"http://someHost.com/someDir", "/someDir/"},
}

func TestHostHandlers(t *testing.T) {
	defer afterTest(t)
	mux := NewServeMux()
	for _, h := range handlers {
		mux.Handle(h.pattern, stringHandler(h.msg))
	}
	ts := httptest.NewServer(mux)
	defer ts.Close()

	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer conn.Close()
	cc := httputil.NewClientConn(conn, nil)
	for _, vt := range vtests {
		var r *Response
		var req Request
		if req.URL, err = url.Parse(vt.url); err != nil {
			t.Errorf("cannot parse url: %v", err)
			continue
		}
		if err := cc.Write(&req); err != nil {
			t.Errorf("writing request: %v", err)
			continue
		}
		r, err := cc.Read(&req)
		if err != nil {
			t.Errorf("reading response: %v", err)
			continue
		}
		switch r.StatusCode {
		case StatusOK:
			s := r.Header.Get("Result")
			if s != vt.expected {
				t.Errorf("Get(%q) = %q, want %q", vt.url, s, vt.expected)
			}
		case StatusMovedPermanently:
			s := r.Header.Get("Location")
			if s != vt.expected {
				t.Errorf("Get(%q) = %q, want %q", vt.url, s, vt.expected)
			}
		default:
			t.Errorf("Get(%q) unhandled status code %d", vt.url, r.StatusCode)
		}
	}
}

var serveMuxRegister = []struct {
	pattern string
	h       Handler
}{
	{"/dir/", serve(200)},
	{"/search", serve(201)},
	{"codesearch.google.com/search", serve(202)},
	{"codesearch.google.com/", serve(203)},
	{"example.com/", HandlerFunc(checkQueryStringHandler)},
}

// serve returns a handler that sends a response with the given code.
func serve(code int) HandlerFunc {
	return func(w ResponseWriter, r *Request) {
		w.WriteHeader(code)
	}
}

// checkQueryStringHandler checks if r.URL.RawQuery has the same value
// as the URL excluding the scheme and the query string and sends 200
// response code if it is, 500 otherwise.
func checkQueryStringHandler(w ResponseWriter, r *Request) {
	u := *r.URL
	u.Scheme = "http"
	u.Host = r.Host
	u.RawQuery = ""
	if "http://"+r.URL.RawQuery == u.String() {
		w.WriteHeader(200)
	} else {
		w.WriteHeader(500)
	}
}

var serveMuxTests = []struct {
	method  string
	host    string
	path    string
	code    int
	pattern string
}{
	{"GET", "google.com", "/", 404, ""},
	{"GET", "google.com", "/dir", 301, "/dir/"},
	{"GET", "google.com", "/dir/", 200, "/dir/"},
	{"GET", "google.com", "/dir/file", 200, "/dir/"},
	{"GET", "google.com", "/search", 201, "/search"},
	{"GET", "google.com", "/search/", 404, ""},
	{"GET", "google.com", "/search/foo", 404, ""},
	{"GET", "codesearch.google.com", "/search", 202, "codesearch.google.com/search"},
	{"GET", "codesearch.google.com", "/search/", 203, "codesearch.google.com/"},
	{"GET", "codesearch.google.com", "/search/foo", 203, "codesearch.google.com/"},
	{"GET", "codesearch.google.com", "/", 203, "codesearch.google.com/"},
	{"GET", "images.google.com", "/search", 201, "/search"},
	{"GET", "images.google.com", "/search/", 404, ""},
	{"GET", "images.google.com", "/search/foo", 404, ""},
	{"GET", "google.com", "/../search", 301, "/search"},
	{"GET", "google.com", "/dir/..", 301, ""},
	{"GET", "google.com", "/dir/..", 301, ""},
	{"GET", "google.com", "/dir/./file", 301, "/dir/"},

	// The /foo -> /foo/ redirect applies to CONNECT requests
	// but the path canonicalization does not.
	{"CONNECT", "google.com", "/dir", 301, "/dir/"},
	{"CONNECT", "google.com", "/../search", 404, ""},
	{"CONNECT", "google.com", "/dir/..", 200, "/dir/"},
	{"CONNECT", "google.com", "/dir/..", 200, "/dir/"},
	{"CONNECT", "google.com", "/dir/./file", 200, "/dir/"},
}

func TestServeMuxHandler(t *testing.T) {
	mux := NewServeMux()
	for _, e := range serveMuxRegister {
		mux.Handle(e.pattern, e.h)
	}

	for _, tt := range serveMuxTests {
		r := &Request{
			Method: tt.method,
			Host:   tt.host,
			URL: &url.URL{
				Path: tt.path,
			},
		}
		h, pattern := mux.Handler(r)
		rr := httptest.NewRecorder()
		h.ServeHTTP(rr, r)
		if pattern != tt.pattern || rr.Code != tt.code {
			t.Errorf("%s %s %s = %d, %q, want %d, %q", tt.method, tt.host, tt.path, rr.Code, pattern, tt.code, tt.pattern)
		}
	}
}

var serveMuxTests2 = []struct {
	method  string
	host    string
	url     string
	code    int
	redirOk bool
}{
	{"GET", "google.com", "/", 404, false},
	{"GET", "example.com", "/test/?example.com/test/", 200, false},
	{"GET", "example.com", "test/?example.com/test/", 200, true},
}

// TestServeMuxHandlerRedirects tests that automatic redirects generated by
// mux.Handler() shouldn't clear the request's query string.
func TestServeMuxHandlerRedirects(t *testing.T) {
	mux := NewServeMux()
	for _, e := range serveMuxRegister {
		mux.Handle(e.pattern, e.h)
	}

	for _, tt := range serveMuxTests2 {
		tries := 1
		turl := tt.url
		for tries > 0 {
			u, e := url.Parse(turl)
			if e != nil {
				t.Fatal(e)
			}
			r := &Request{
				Method: tt.method,
				Host:   tt.host,
				URL:    u,
			}
			h, _ := mux.Handler(r)
			rr := httptest.NewRecorder()
			h.ServeHTTP(rr, r)
			if rr.Code != 301 {
				if rr.Code != tt.code {
					t.Errorf("%s %s %s = %d, want %d", tt.method, tt.host, tt.url, rr.Code, tt.code)
				}
				break
			}
			if !tt.redirOk {
				t.Errorf("%s %s %s, unexpected redirect", tt.method, tt.host, tt.url)
				break
			}
			turl = rr.HeaderMap.Get("Location")
			tries--
		}
		if tries < 0 {
			t.Errorf("%s %s %s, too many redirects", tt.method, tt.host, tt.url)
		}
	}
}

// Tests for https://golang.org/issue/900
func TestMuxRedirectLeadingSlashes(t *testing.T) {
	paths := []string{"//foo.txt", "///foo.txt", "/../../foo.txt"}
	for _, path := range paths {
		req, err := ReadRequest(bufio.NewReader(strings.NewReader("GET " + path + " HTTP/1.1\r\nHost: test\r\n\r\n")))
		if err != nil {
			t.Errorf("%s", err)
		}
		mux := NewServeMux()
		resp := httptest.NewRecorder()

		mux.ServeHTTP(resp, req)

		if loc, expected := resp.Header().Get("Location"), "/foo.txt"; loc != expected {
			t.Errorf("Expected Location header set to %q; got %q", expected, loc)
			return
		}

		if code, expected := resp.Code, StatusMovedPermanently; code != expected {
			t.Errorf("Expected response code of StatusMovedPermanently; got %d", code)
			return
		}
	}
}

func TestServerTimeouts(t *testing.T) {
	if runtime.GOOS == "plan9" {
		t.Skip("skipping test; see https://golang.org/issue/7237")
	}
	defer afterTest(t)
	reqNum := 0
	ts := httptest.NewUnstartedServer(HandlerFunc(func(res ResponseWriter, req *Request) {
		reqNum++
		fmt.Fprintf(res, "req=%d", reqNum)
	}))
	ts.Config.ReadTimeout = 250 * time.Millisecond
	ts.Config.WriteTimeout = 250 * time.Millisecond
	ts.Start()
	defer ts.Close()

	// Hit the HTTP server successfully.
	tr := &Transport{DisableKeepAlives: true} // they interfere with this test
	defer tr.CloseIdleConnections()
	c := &Client{Transport: tr}
	r, err := c.Get(ts.URL)
	if err != nil {
		t.Fatalf("http Get #1: %v", err)
	}
	got, _ := ioutil.ReadAll(r.Body)
	expected := "req=1"
	if string(got) != expected {
		t.Errorf("Unexpected response for request #1; got %q; expected %q",
			string(got), expected)
	}

	// Slow client that should timeout.
	t1 := time.Now()
	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
	if err != nil {
		t.Fatalf("Dial: %v", err)
	}
	buf := make([]byte, 1)
	n, err := conn.Read(buf)
	latency := time.Since(t1)
	if n != 0 || err != io.EOF {
		t.Errorf("Read = %v, %v, wanted %v, %v", n, err, 0, io.EOF)
	}
	if latency < 200*time.Millisecond /* fudge from 250 ms above */ {
		t.Errorf("got EOF after %s, want >= %s", latency, 200*time.Millisecond)
	}

	// Hit the HTTP server successfully again, verifying that the
	// previous slow connection didn't run our handler.  (that we
	// get "req=2", not "req=3")
	r, err = Get(ts.URL)
	if err != nil {
		t.Fatalf("http Get #2: %v", err)
	}
	got, _ = ioutil.ReadAll(r.Body)
	expected = "req=2"
	if string(got) != expected {
		t.Errorf("Get #2 got %q, want %q", string(got), expected)
	}

	if !testing.Short() {
		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
		if err != nil {
			t.Fatalf("Dial: %v", err)
		}
		defer conn.Close()
		go io.Copy(ioutil.Discard, conn)
		for i := 0; i < 5; i++ {
			_, err := conn.Write([]byte("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"))
			if err != nil {
				t.Fatalf("on write %d: %v", i, err)
			}
			time.Sleep(ts.Config.ReadTimeout / 2)
		}
	}
}

// golang.org/issue/4741 -- setting only a write timeout that triggers
// shouldn't cause a handler to block forever on reads (next HTTP
// request) that will never happen.
func TestOnlyWriteTimeout(t *testing.T) {
	if runtime.GOOS == "plan9" {
		t.Skip("skipping test; see https://golang.org/issue/7237")
	}
	defer afterTest(t)
	var conn net.Conn
	var afterTimeoutErrc = make(chan error, 1)
	ts := httptest.NewUnstartedServer(HandlerFunc(func(w ResponseWriter, req *Request) {
		buf := make([]byte, 512<<10)
		_, err := w.Write(buf)
		if err != nil {
			t.Errorf("handler Write error: %v", err)
			return
		}
		conn.SetWriteDeadline(time.Now().Add(-30 * time.Second))
		_, err = w.Write(buf)
		afterTimeoutErrc <- err
	}))
	ts.Listener = trackLastConnListener{ts.Listener, &conn}
	ts.Start()
	defer ts.Close()

	tr := &Transport{DisableKeepAlives: false}
	defer tr.CloseIdleConnections()
	c := &Client{Transport: tr}

	errc := make(chan error)
	go func() {
		res, err := c.Get(ts.URL)
		if err != nil {
			errc <- err
			return
		}
		_, err = io.Copy(ioutil.Discard, res.Body)
		errc <- err
	}()
	select {
	case err := <-errc:
		if err == nil {
			t.Errorf("expected an error from Get request")
		}
	case <-time.After(5 * time.Second):
		t.Fatal("timeout waiting for Get error")
	}
	if err := <-afterTimeoutErrc; err == nil {
		t.Error("expected write error after timeout")
	}
}

// trackLastConnListener tracks the last net.Conn that was accepted.
type trackLastConnListener struct {
	net.Listener
	last *net.Conn // destination
}

func (l trackLastConnListener) Accept() (c net.Conn, err error) {
	c, err = l.Listener.Accept()
	*l.last = c
	return
}

// TestIdentityResponse verifies that a handler can unset
func TestIdentityResponse(t *testing.T) {
	defer afterTest(t)
	handler := HandlerFunc(func(rw ResponseWriter, req *Request) {
		rw.Header().Set("Content-Length", "3")
		rw.Header().Set("Transfer-Encoding", req.FormValue("te"))
		switch {
		case req.FormValue("overwrite") == "1":
			_, err := rw.Write([]byte("foo TOO LONG"))
			if err != ErrContentLength {
				t.Errorf("expected ErrContentLength; got %v", err)
			}
		case req.FormValue("underwrite") == "1":
			rw.Header().Set("Content-Length", "500")
			rw.Write([]byte("too short"))
		default:
			rw.Write([]byte("foo"))
		}
	})

	ts := httptest.NewServer(handler)
	defer ts.Close()

	// Note: this relies on the assumption (which is true) that
	// Get sends HTTP/1.1 or greater requests.  Otherwise the
	// server wouldn't have the choice to send back chunked
	// responses.
	for _, te := range []string{"", "identity"} {
		url := ts.URL + "/?te=" + te
		res, err := Get(url)
		if err != nil {
			t.Fatalf("error with Get of %s: %v", url, err)
		}
		if cl, expected := res.ContentLength, int64(3); cl != expected {
			t.Errorf("for %s expected res.ContentLength of %d; got %d", url, expected, cl)
		}
		if cl, expected := res.Header.Get("Content-Length"), "3"; cl != expected {
			t.Errorf("for %s expected Content-Length header of %q; got %q", url, expected, cl)
		}
		if tl, expected := len(res.TransferEncoding), 0; tl != expected {
			t.Errorf("for %s expected len(res.TransferEncoding) of %d; got %d (%v)",
				url, expected, tl, res.TransferEncoding)
		}
		res.Body.Close()
	}

	// Verify that ErrContentLength is returned
	url := ts.URL + "/?overwrite=1"
	res, err := Get(url)
	if err != nil {
		t.Fatalf("error with Get of %s: %v", url, err)
	}
	res.Body.Close()

	// Verify that the connection is closed when the declared Content-Length
	// is larger than what the handler wrote.
	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
	if err != nil {
		t.Fatalf("error dialing: %v", err)
	}
	_, err = conn.Write([]byte("GET /?underwrite=1 HTTP/1.1\r\nHost: foo\r\n\r\n"))
	if err != nil {
		t.Fatalf("error writing: %v", err)
	}

	// The ReadAll will hang for a failing test, so use a Timer to
	// fail explicitly.
	goTimeout(t, 2*time.Second, func() {
		got, _ := ioutil.ReadAll(conn)
		expectedSuffix := "\r\n\r\ntoo short"
		if !strings.HasSuffix(string(got), expectedSuffix) {
			t.Errorf("Expected output to end with %q; got response body %q",
				expectedSuffix, string(got))
		}
	})
}

func testTCPConnectionCloses(t *testing.T, req string, h Handler) {
	defer afterTest(t)
	s := httptest.NewServer(h)
	defer s.Close()

	conn, err := net.Dial("tcp", s.Listener.Addr().String())
	if err != nil {
		t.Fatal("dial error:", err)
	}
	defer conn.Close()

	_, err = fmt.Fprint(conn, req)
	if err != nil {
		t.Fatal("print error:", err)
	}

	r := bufio.NewReader(conn)
	res, err := ReadResponse(r, &Request{Method: "GET"})
	if err != nil {
		t.Fatal("ReadResponse error:", err)
	}

	didReadAll := make(chan bool, 1)
	go func() {
		select {
		case <-time.After(5 * time.Second):
			t.Error("body not closed after 5s")
			return
		case <-didReadAll:
		}
	}()

	_, err = ioutil.ReadAll(r)
	if err != nil {
		t.Fatal("read error:", err)
	}
	didReadAll <- true

	if !res.Close {
		t.Errorf("Response.Close = false; want true")
	}
}

// TestServeHTTP10Close verifies that HTTP/1.0 requests won't be kept alive.
func TestServeHTTP10Close(t *testing.T) {
	testTCPConnectionCloses(t, "GET / HTTP/1.0\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
		ServeFile(w, r, "testdata/file")
	}))
}

// TestClientCanClose verifies that clients can also force a connection to close.
func TestClientCanClose(t *testing.T) {
	testTCPConnectionCloses(t, "GET / HTTP/1.1\r\nConnection: close\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
		// Nothing.
	}))
}

// TestHandlersCanSetConnectionClose verifies that handlers can force a connection to close,
// even for HTTP/1.1 requests.
func TestHandlersCanSetConnectionClose11(t *testing.T) {
	testTCPConnectionCloses(t, "GET / HTTP/1.1\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
		w.Header().Set("Connection", "close")
	}))
}

func TestHandlersCanSetConnectionClose10(t *testing.T) {
	testTCPConnectionCloses(t, "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
		w.Header().Set("Connection", "close")
	}))
}

func TestSetsRemoteAddr(t *testing.T) {
	defer afterTest(t)
	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		fmt.Fprintf(w, "%s", r.RemoteAddr)
	}))
	defer ts.Close()

	res, err := Get(ts.URL)
	if err != nil {
		t.Fatalf("Get error: %v", err)
	}
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		t.Fatalf("ReadAll error: %v", err)
	}
	ip := string(body)
	if !strings.HasPrefix(ip, "127.0.0.1:") && !strings.HasPrefix(ip, "[::1]:") {
		t.Fatalf("Expected local addr; got %q", ip)
	}
}

func TestChunkedResponseHeaders(t *testing.T) {
	defer afterTest(t)
	log.SetOutput(ioutil.Discard) // is noisy otherwise
	defer log.SetOutput(os.Stderr)

	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		w.Header().Set("Content-Length", "intentional gibberish") // we check that this is deleted
		w.(Flusher).Flush()
		fmt.Fprintf(w, "I am a chunked response.")
	}))
	defer ts.Close()

	res, err := Get(ts.URL)
	if err != nil {
		t.Fatalf("Get error: %v", err)
	}
	defer res.Body.Close()
	if g, e := res.ContentLength, int64(-1); g != e {
		t.Errorf("expected ContentLength of %d; got %d", e, g)
	}
	if g, e := res.TransferEncoding, []string{"chunked"}; !reflect.DeepEqual(g, e) {
		t.Errorf("expected TransferEncoding of %v; got %v", e, g)
	}
	if _, haveCL := res.Header["Content-Length"]; haveCL {
		t.Errorf("Unexpected Content-Length")
	}
}

func TestIdentityResponseHeaders(t *testing.T) {
	defer afterTest(t)
	log.SetOutput(ioutil.Discard) // is noisy otherwise
	defer log.SetOutput(os.Stderr)

	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		w.Header().Set("Transfer-Encoding", "identity")
		w.(Flusher).Flush()
		fmt.Fprintf(w, "I am an identity response.")
	}))
	defer ts.Close()

	res, err := Get(ts.URL)
	if err != nil {
		t.Fatalf("Get error: %v", err)
	}
	defer res.Body.Close()

	if g, e := res.TransferEncoding, []string(nil); !reflect.DeepEqual(g, e) {
		t.Errorf("expected TransferEncoding of %v; got %v", e, g)
	}
	if _, haveCL := res.Header["Content-Length"]; haveCL {
		t.Errorf("Unexpected Content-Length")
	}
	if !res.Close {
		t.Errorf("expected Connection: close; got %v", res.Close)
	}
}

// Test304Responses verifies that 304s don't declare that they're
// chunking in their response headers and aren't allowed to produce
// output.
func Test304Responses(t *testing.T) {
	defer afterTest(t)
	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		w.WriteHeader(StatusNotModified)
		_, err := w.Write([]byte("illegal body"))
		if err != ErrBodyNotAllowed {
			t.Errorf("on Write, expected ErrBodyNotAllowed, got %v", err)
		}
	}))
	defer ts.Close()
	res, err := Get(ts.URL)
	if err != nil {
		t.Error(err)
	}
	if len(res.TransferEncoding) > 0 {
		t.Errorf("expected no TransferEncoding; got %v", res.TransferEncoding)
	}
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		t.Error(err)
	}
	if len(body) > 0 {
		t.Errorf("got unexpected body %q", string(body))
	}
}

// TestHeadResponses verifies that all MIME type sniffing and Content-Length
// counting of GET requests also happens on HEAD requests.
func TestHeadResponses(t *testing.T) {
	defer afterTest(t)
	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		_, err := w.Write([]byte("<html>"))
		if err != nil {
			t.Errorf("ResponseWriter.Write: %v", err)
		}

		// Also exercise the ReaderFrom path
		_, err = io.Copy(w, strings.NewReader("789a"))
		if err != nil {
			t.Errorf("Copy(ResponseWriter, ...): %v", err)
		}
	}))
	defer ts.Close()
	res, err := Head(ts.URL)
	if err != nil {
		t.Error(err)
	}
	if len(res.TransferEncoding) > 0 {
		t.Errorf("expected no TransferEncoding; got %v", res.TransferEncoding)
	}
	if ct := res.Header.Get("Content-Type"); ct != "text/html; charset=utf-8" {
		t.Errorf("Content-Type: %q; want text/html; charset=utf-8", ct)
	}
	if v := res.ContentLength; v != 10 {
		t.Errorf("Content-Length: %d; want 10", v)
	}
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		t.Error(err)
	}
	if len(body) > 0 {
		t.Errorf("got unexpected body %q", string(body))
	}
}

func TestTLSHandshakeTimeout(t *testing.T) {
	if runtime.GOOS == "plan9" {
		t.Skip("skipping test; see https://golang.org/issue/7237")
	}
	defer afterTest(t)
	ts := httptest.NewUnstartedServer(HandlerFunc(func(w ResponseWriter, r *Request) {}))
	errc := make(chanWriter, 10) // but only expecting 1
	ts.Config.ReadTimeout = 250 * time.Millisecond
	ts.Config.ErrorLog = log.New(errc, "", 0)
	ts.StartTLS()
	defer ts.Close()
	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
	if err != nil {
		t.Fatalf("Dial: %v", err)
	}
	defer conn.Close()
	goTimeout(t, 10*time.Second, func() {
		var buf [1]byte
		n, err := conn.Read(buf[:])
		if err == nil || n != 0 {
			t.Errorf("Read = %d, %v; want an error and no bytes", n, err)
		}
	})
	select {
	case v := <-errc:
		if !strings.Contains(v, "timeout") && !strings.Contains(v, "TLS handshake") {
			t.Errorf("expected a TLS handshake timeout error; got %q", v)
		}
	case <-time.After(5 * time.Second):
		t.Errorf("timeout waiting for logged error")
	}
}

func TestTLSServer(t *testing.T) {
	defer afterTest(t)
	ts := httptest.NewTLSServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		if r.TLS != nil {
			w.Header().Set("X-TLS-Set", "true")
			if r.TLS.HandshakeComplete {
				w.Header().Set("X-TLS-HandshakeComplete", "true")
			}
		}
	}))
	ts.Config.ErrorLog = log.New(ioutil.Discard, "", 0)
	defer ts.Close()

	// Connect an idle TCP connection to this server before we run
	// our real tests.  This idle connection used to block forever
	// in the TLS handshake, preventing future connections from
	// being accepted. It may prevent future accidental blocking
	// in newConn.
	idleConn, err := net.Dial("tcp", ts.Listener.Addr().String())
	if err != nil {
		t.Fatalf("Dial: %v", err)
	}
	defer idleConn.Close()
	goTimeout(t, 10*time.Second, func() {
		if !strings.HasPrefix(ts.URL, "https://") {
			t.Errorf("expected test TLS server to start with https://, got %q", ts.URL)
			return
		}
		noVerifyTransport := &Transport{
			TLSClientConfig: &tls.Config{
				InsecureSkipVerify: true,
			},
		}
		client := &Client{Transport: noVerifyTransport}
		res, err := client.Get(ts.URL)
		if err != nil {
			t.Error(err)
			return
		}
		if res == nil {
			t.Errorf("got nil Response")
			return
		}
		defer res.Body.Close()
		if res.Header.Get("X-TLS-Set") != "true" {
			t.Errorf("expected X-TLS-Set response header")
			return
		}
		if res.Header.Get("X-TLS-HandshakeComplete") != "true" {
			t.Errorf("expected X-TLS-HandshakeComplete header")
		}
	})
}

type serverExpectTest struct {
	contentLength    int // of request body
	chunked          bool
	expectation      string // e.g. "100-continue"
	readBody         bool   // whether handler should read the body (if false, sends StatusUnauthorized)
	expectedResponse string // expected substring in first line of http response
}

func expectTest(contentLength int, expectation string, readBody bool, expectedResponse string) serverExpectTest {
	return serverExpectTest{
		contentLength:    contentLength,
		expectation:      expectation,
		readBody:         readBody,
		expectedResponse: expectedResponse,
	}
}

var serverExpectTests = []serverExpectTest{
	// Normal 100-continues, case-insensitive.
	expectTest(100, "100-continue", true, "100 Continue"),
	expectTest(100, "100-cOntInUE", true, "100 Continue"),

	// No 100-continue.
	expectTest(100, "", true, "200 OK"),

	// 100-continue but requesting client to deny us,
	// so it never reads the body.
	expectTest(100, "100-continue", false, "401 Unauthorized"),
	// Likewise without 100-continue:
	expectTest(100, "", false, "401 Unauthorized"),

	// Non-standard expectations are failures
	expectTest(0, "a-pony", false, "417 Expectation Failed"),

	// Expect-100 requested but no body (is apparently okay: Issue 7625)
	expectTest(0, "100-continue", true, "200 OK"),
	// Expect-100 requested but handler doesn't read the body
	expectTest(0, "100-continue", false, "401 Unauthorized"),
	// Expect-100 continue with no body, but a chunked body.
	{
		expectation:      "100-continue",
		readBody:         true,
		chunked:          true,
		expectedResponse: "100 Continue",
	},
}

// Tests that the server responds to the "Expect" request header
// correctly.
func TestServerExpect(t *testing.T) {
	defer afterTest(t)
	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		// Note using r.FormValue("readbody") because for POST
		// requests that would read from r.Body, which we only
		// conditionally want to do.
		if strings.Contains(r.URL.RawQuery, "readbody=true") {
			ioutil.ReadAll(r.Body)
			w.Write([]byte("Hi"))
		} else {
			w.WriteHeader(StatusUnauthorized)
		}
	}))
	defer ts.Close()

	runTest := func(test serverExpectTest) {
		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
		if err != nil {
			t.Fatalf("Dial: %v", err)
		}
		defer conn.Close()

		// Only send the body immediately if we're acting like an HTTP client
		// that doesn't send 100-continue expectations.
		writeBody := test.contentLength != 0 && strings.ToLower(test.expectation) != "100-continue"

		go func() {
			contentLen := fmt.Sprintf("Content-Length: %d", test.contentLength)
			if test.chunked {
				contentLen = "Transfer-Encoding: chunked"
			}
			_, err := fmt.Fprintf(conn, "POST /?readbody=%v HTTP/1.1\r\n"+
				"Connection: close\r\n"+
				"%s\r\n"+
				"Expect: %s\r\nHost: foo\r\n\r\n",
				test.readBody, contentLen, test.expectation)
			if err != nil {
				t.Errorf("On test %#v, error writing request headers: %v", test, err)
				return
			}
			if writeBody {
				var targ io.WriteCloser = struct {
					io.Writer
					io.Closer
				}{
					conn,
					ioutil.NopCloser(nil),
				}
				if test.chunked {
					targ = httputil.NewChunkedWriter(conn)
				}
				body := strings.Repeat("A", test.contentLength)
				_, err = fmt.Fprint(targ, body)
				if err == nil {
					err = targ.Close()
				}
				if err != nil {
					if !test.readBody {
						// Server likely already hung up on us.
						// See larger comment below.
						t.Logf("On test %#v, acceptable error writing request body: %v", test, err)
						return
					}
					t.Errorf("On test %#v, error writing request body: %v", test, err)
				}
			}
		}()
		bufr := bufio.NewReader(conn)
		line, err := bufr.ReadString('\n')
		if err != nil {
			if writeBody && !test.readBody {
				// This is an acceptable failure due to a possible TCP race:
				// We were still writing data and the server hung up on us. A TCP
				// implementation may send a RST if our request body data was known
				// to be lost, which may trigger our reads to fail.
				// See RFC 1122 page 88.
				t.Logf("On test %#v, acceptable error from ReadString: %v", test, err)
				return
			}
			t.Fatalf("On test %#v, ReadString: %v", test, err)
		}
		if !strings.Contains(line, test.expectedResponse) {
			t.Errorf("On test %#v, got first line = %q; want %q", test, line, test.expectedResponse)
		}
	}

	for _, test := range serverExpectTests {
		runTest(test)
	}
}

// Under a ~256KB (maxPostHandlerReadBytes) threshold, the server
// should consume client request bodies that a handler didn't read.
func TestServerUnreadRequestBodyLittle(t *testing.T) {
	defer afterTest(t)
	conn := new(testConn)
	body := strings.Repeat("x", 100<<10)
	conn.readBuf.Write([]byte(fmt.Sprintf(
		"POST / HTTP/1.1\r\n"+
			"Host: test\r\n"+
			"Content-Length: %d\r\n"+
			"\r\n", len(body))))
	conn.readBuf.Write([]byte(body))

	done := make(chan bool)

	ls := &oneConnListener{conn}
	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
		defer close(done)
		if conn.readBuf.Len() < len(body)/2 {
			t.Errorf("on request, read buffer length is %d; expected about 100 KB", conn.readBuf.Len())
		}
		rw.WriteHeader(200)
		rw.(Flusher).Flush()
		if g, e := conn.readBuf.Len(), 0; g != e {
			t.Errorf("after WriteHeader, read buffer length is %d; want %d", g, e)
		}
		if c := rw.Header().Get("Connection"); c != "" {
			t.Errorf(`Connection header = %q; want ""`, c)
		}
	}))
	<-done
}

// Over a ~256KB (maxPostHandlerReadBytes) threshold, the server
// should ignore client request bodies that a handler didn't read
// and close the connection.
func TestServerUnreadRequestBodyLarge(t *testing.T) {
	conn := new(testConn)
	body := strings.Repeat("x", 1<<20)
	conn.readBuf.Write([]byte(fmt.Sprintf(
		"POST / HTTP/1.1\r\n"+
			"Host: test\r\n"+
			"Content-Length: %d\r\n"+
			"\r\n", len(body))))
	conn.readBuf.Write([]byte(body))
	conn.closec = make(chan bool, 1)

	ls := &oneConnListener{conn}
	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
		if conn.readBuf.Len() < len(body)/2 {
			t.Errorf("on request, read buffer length is %d; expected about 1MB", conn.readBuf.Len())
		}
		rw.WriteHeader(200)
		rw.(Flusher).Flush()
		if conn.readBuf.Len() < len(body)/2 {
			t.Errorf("post-WriteHeader, read buffer length is %d; expected about 1MB", conn.readBuf.Len())
		}
	}))
	<-conn.closec

	if res := conn.writeBuf.String(); !strings.Contains(res, "Connection: close") {
		t.Errorf("Expected a Connection: close header; got response: %s", res)
	}
}

type handlerBodyCloseTest struct {
	bodySize     int
	bodyChunked  bool
	reqConnClose bool

	wantEOFSearch bool // should Handler's Body.Close do Reads, looking for EOF?
	wantNextReq   bool // should it find the next request on the same conn?
}

func (t handlerBodyCloseTest) connectionHeader() string {
	if t.reqConnClose {
		return "Connection: close\r\n"
	}
	return ""
}

var handlerBodyCloseTests = [...]handlerBodyCloseTest{
	// Small enough to slurp past to the next request +
	// has Content-Length.
	0: {
		bodySize:      20 << 10,
		bodyChunked:   false,
		reqConnClose:  false,
		wantEOFSearch: true,
		wantNextReq:   true,
	},

	// Small enough to slurp past to the next request +
	// is chunked.
	1: {
		bodySize:      20 << 10,
		bodyChunked:   true,
		reqConnClose:  false,
		wantEOFSearch: true,
		wantNextReq:   true,
	},

	// Small enough to slurp past to the next request +
	// has Content-Length +
	// declares Connection: close (so pointless to read more).
	2: {
		bodySize:      20 << 10,
		bodyChunked:   false,
		reqConnClose:  true,
		wantEOFSearch: false,
		wantNextReq:   false,
	},

	// Small enough to slurp past to the next request +
	// declares Connection: close,
	// but chunked, so it might have trailers.
	// TODO: maybe skip this search if no trailers were declared
	// in the headers.
	3: {
		bodySize:      20 << 10,
		bodyChunked:   true,
		reqConnClose:  true,
		wantEOFSearch: true,
		wantNextReq:   false,
	},

	// Big with Content-Length, so give up immediately if we know it's too big.
	4: {
		bodySize:      1 << 20,
		bodyChunked:   false, // has a Content-Length
		reqConnClose:  false,
		wantEOFSearch: false,
		wantNextReq:   false,
	},

	// Big chunked, so read a bit before giving up.
	5: {
		bodySize:      1 << 20,
		bodyChunked:   true,
		reqConnClose:  false,
		wantEOFSearch: true,
		wantNextReq:   false,
	},

	// Big with Connection: close, but chunked, so search for trailers.
	// TODO: maybe skip this search if no trailers were declared
	// in the headers.
	6: {
		bodySize:      1 << 20,
		bodyChunked:   true,
		reqConnClose:  true,
		wantEOFSearch: true,
		wantNextReq:   false,
	},

	// Big with Connection: close, so don't do any reads on Close.
	// With Content-Length.
	7: {
		bodySize:      1 << 20,
		bodyChunked:   false,
		reqConnClose:  true,
		wantEOFSearch: false,
		wantNextReq:   false,
	},
}

func TestHandlerBodyClose(t *testing.T) {
	for i, tt := range handlerBodyCloseTests {
		testHandlerBodyClose(t, i, tt)
	}
}

func testHandlerBodyClose(t *testing.T, i int, tt handlerBodyCloseTest) {
	conn := new(testConn)
	body := strings.Repeat("x", tt.bodySize)
	if tt.bodyChunked {
		conn.readBuf.WriteString("POST / HTTP/1.1\r\n" +
			"Host: test\r\n" +
			tt.connectionHeader() +
			"Transfer-Encoding: chunked\r\n" +
			"\r\n")
		cw := internal.NewChunkedWriter(&conn.readBuf)
		io.WriteString(cw, body)
		cw.Close()
		conn.readBuf.WriteString("\r\n")
	} else {
		conn.readBuf.Write([]byte(fmt.Sprintf(
			"POST / HTTP/1.1\r\n"+
				"Host: test\r\n"+
				tt.connectionHeader()+
				"Content-Length: %d\r\n"+
				"\r\n", len(body))))
		conn.readBuf.Write([]byte(body))
	}
	if !tt.reqConnClose {
		conn.readBuf.WriteString("GET / HTTP/1.1\r\nHost: test\r\n\r\n")
	}
	conn.closec = make(chan bool, 1)

	ls := &oneConnListener{conn}
	var numReqs int
	var size0, size1 int
	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
		numReqs++
		if numReqs == 1 {
			size0 = conn.readBuf.Len()
			req.Body.Close()
			size1 = conn.readBuf.Len()
		}
	}))
	<-conn.closec
	if numReqs < 1 || numReqs > 2 {
		t.Fatalf("%d. bug in test. unexpected number of requests = %d", i, numReqs)
	}
	didSearch := size0 != size1
	if didSearch != tt.wantEOFSearch {
		t.Errorf("%d. did EOF search = %v; want %v (size went from %d to %d)", i, didSearch, !didSearch, size0, size1)
	}
	if tt.wantNextReq && numReqs != 2 {
		t.Errorf("%d. numReq = %d; want 2", i, numReqs)
	}
}

// testHandlerBodyConsumer represents a function injected into a test handler to
// vary work done on a request Body.
type testHandlerBodyConsumer struct {
	name string
	f    func(io.ReadCloser)
}

var testHandlerBodyConsumers = []testHandlerBodyConsumer{
	{"nil", func(io.ReadCloser) {}},
	{"close", func(r io.ReadCloser) { r.Close() }},
	{"discard", func(r io.ReadCloser) { io.Copy(ioutil.Discard, r) }},
}

func TestRequestBodyReadErrorClosesConnection(t *testing.T) {
	defer afterTest(t)
	for _, handler := range testHandlerBodyConsumers {
		conn := new(testConn)
		conn.readBuf.WriteString("POST /public HTTP/1.1\r\n" +
			"Host: test\r\n" +
			"Transfer-Encoding: chunked\r\n" +
			"\r\n" +
			"hax\r\n" + // Invalid chunked encoding
			"GET /secret HTTP/1.1\r\n" +
			"Host: test\r\n" +
			"\r\n")

		conn.closec = make(chan bool, 1)
		ls := &oneConnListener{conn}
		var numReqs int
		go Serve(ls, HandlerFunc(func(_ ResponseWriter, req *Request) {
			numReqs++
			if strings.Contains(req.URL.Path, "secret") {
				t.Error("Request for /secret encountered, should not have happened.")
			}
			handler.f(req.Body)
		}))
		<-conn.closec
		if numReqs != 1 {
			t.Errorf("Handler %v: got %d reqs; want 1", handler.name, numReqs)
		}
	}
}

func TestInvalidTrailerClosesConnection(t *testing.T) {
	defer afterTest(t)
	for _, handler := range testHandlerBodyConsumers {
		conn := new(testConn)
		conn.readBuf.WriteString("POST /public HTTP/1.1\r\n" +
			"Host: test\r\n" +
			"Trailer: hack\r\n" +
			"Transfer-Encoding: chunked\r\n" +
			"\r\n" +
			"3\r\n" +
			"hax\r\n" +
			"0\r\n" +
			"I'm not a valid trailer\r\n" +
			"GET /secret HTTP/1.1\r\n" +
			"Host: test\r\n" +
			"\r\n")

		conn.closec = make(chan bool, 1)
		ln := &oneConnListener{conn}
		var numReqs int
		go Serve(ln, HandlerFunc(func(_ ResponseWriter, req *Request) {
			numReqs++
			if strings.Contains(req.URL.Path, "secret") {
				t.Errorf("Handler %s, Request for /secret encountered, should not have happened.", handler.name)
			}
			handler.f(req.Body)
		}))
		<-conn.closec
		if numReqs != 1 {
			t.Errorf("Handler %s: got %d reqs; want 1", handler.name, numReqs)
		}
	}
}

// slowTestConn is a net.Conn that provides a means to simulate parts of a
// request being received piecemeal. Deadlines can be set and enforced in both
// Read and Write.
type slowTestConn struct {
	// over multiple calls to Read, time.Durations are slept, strings are read.
	script []interface{}
	closec chan bool
	rd, wd time.Time // read, write deadline
	noopConn
}

func (c *slowTestConn) SetDeadline(t time.Time) error {
	c.SetReadDeadline(t)
	c.SetWriteDeadline(t)
	return nil
}

func (c *slowTestConn) SetReadDeadline(t time.Time) error {
	c.rd = t
	return nil
}

func (c *slowTestConn) SetWriteDeadline(t time.Time) error {
	c.wd = t
	return nil
}

func (c *slowTestConn) Read(b []byte) (n int, err error) {
restart:
	if !c.rd.IsZero() && time.Now().After(c.rd) {
		return 0, syscall.ETIMEDOUT
	}
	if len(c.script) == 0 {
		return 0, io.EOF
	}

	switch cue := c.script[0].(type) {
	case time.Duration:
		if !c.rd.IsZero() {
			// If the deadline falls in the middle of our sleep window, deduct
			// part of the sleep, then return a timeout.
			if remaining := c.rd.Sub(time.Now()); remaining < cue {
				c.script[0] = cue - remaining
				time.Sleep(remaining)
				return 0, syscall.ETIMEDOUT
			}
		}
		c.script = c.script[1:]
		time.Sleep(cue)
		goto restart

	case string:
		n = copy(b, cue)
		// If cue is too big for the buffer, leave the end for the next Read.
		if len(cue) > n {
			c.script[0] = cue[n:]
		} else {
			c.script = c.script[1:]
		}

	default:
		panic("unknown cue in slowTestConn script")
	}

	return
}

func (c *slowTestConn) Close() error {
	select {
	case c.closec <- true:
	default:
	}
	return nil
}

func (c *slowTestConn) Write(b []byte) (int, error) {
	if !c.wd.IsZero() && time.Now().After(c.wd) {
		return 0, syscall.ETIMEDOUT
	}
	return len(b), nil
}

func TestRequestBodyTimeoutClosesConnection(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping in -short mode")
	}
	defer afterTest(t)
	for _, handler := range testHandlerBodyConsumers {
		conn := &slowTestConn{
			script: []interface{}{
				"POST /public HTTP/1.1\r\n" +
					"Host: test\r\n" +
					"Content-Length: 10000\r\n" +
					"\r\n",
				"foo bar baz",
				600 * time.Millisecond, // Request deadline should hit here
				"GET /secret HTTP/1.1\r\n" +
					"Host: test\r\n" +
					"\r\n",
			},
			closec: make(chan bool, 1),
		}
		ls := &oneConnListener{conn}

		var numReqs int
		s := Server{
			Handler: HandlerFunc(func(_ ResponseWriter, req *Request) {
				numReqs++
				if strings.Contains(req.URL.Path, "secret") {
					t.Error("Request for /secret encountered, should not have happened.")
				}
				handler.f(req.Body)
			}),
			ReadTimeout: 400 * time.Millisecond,
		}
		go s.Serve(ls)
		<-conn.closec

		if numReqs != 1 {
			t.Errorf("Handler %v: got %d reqs; want 1", handler.name, numReqs)
		}
	}
}

func TestTimeoutHandler(t *testing.T) {
	defer afterTest(t)
	sendHi := make(chan bool, 1)
	writeErrors := make(chan error, 1)
	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
		<-sendHi
		_, werr := w.Write([]byte("hi"))
		writeErrors <- werr
	})
	timeout := make(chan time.Time, 1) // write to this to force timeouts
	ts := httptest.NewServer(NewTestTimeoutHandler(sayHi, timeout))
	defer ts.Close()

	// Succeed without timing out:
	sendHi <- true
	res, err := Get(ts.URL)
	if err != nil {
		t.Error(err)
	}
	if g, e := res.StatusCode, StatusOK; g != e {
		t.Errorf("got res.StatusCode %d; expected %d", g, e)
	}
	body, _ := ioutil.ReadAll(res.Body)
	if g, e := string(body), "hi"; g != e {
		t.Errorf("got body %q; expected %q", g, e)
	}
	if g := <-writeErrors; g != nil {
		t.Errorf("got unexpected Write error on first request: %v", g)
	}

	// Times out:
	timeout <- time.Time{}
	res, err = Get(ts.URL)
	if err != nil {
		t.Error(err)
	}
	if g, e := res.StatusCode, StatusServiceUnavailable; g != e {
		t.Errorf("got res.StatusCode %d; expected %d", g, e)
	}
	body, _ = ioutil.ReadAll(res.Body)
	if !strings.Contains(string(body), "<title>Timeout</title>") {
		t.Errorf("expected timeout body; got %q", string(body))
	}

	// Now make the previously-timed out handler speak again,
	// which verifies the panic is handled:
	sendHi <- true
	if g, e := <-writeErrors, ErrHandlerTimeout; g != e {
		t.Errorf("expected Write error of %v; got %v", e, g)
	}
}

// See issues 8209 and 8414.
func TestTimeoutHandlerRace(t *testing.T) {
	defer afterTest(t)

	delayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
		ms, _ := strconv.Atoi(r.URL.Path[1:])
		if ms == 0 {
			ms = 1
		}
		for i := 0; i < ms; i++ {
			w.Write([]byte("hi"))
			time.Sleep(time.Millisecond)
		}
	})

	ts := httptest.NewServer(TimeoutHandler(delayHi, 20*time.Millisecond, ""))
	defer ts.Close()

	var wg sync.WaitGroup
	gate := make(chan bool, 10)
	n := 50
	if testing.Short() {
		n = 10
		gate = make(chan bool, 3)
	}
	for i := 0; i < n; i++ {
		gate <- true
		wg.Add(1)
		go func() {
			defer wg.Done()
			defer func() { <-gate }()
			res, err := Get(fmt.Sprintf("%s/%d", ts.URL, rand.Intn(50)))
			if err == nil {
				io.Copy(ioutil.Discard, res.Body)
				res.Body.Close()
			}
		}()
	}
	wg.Wait()
}

// See issues 8209 and 8414.
func TestTimeoutHandlerRaceHeader(t *testing.T) {
	defer afterTest(t)

	delay204 := HandlerFunc(func(w ResponseWriter, r *Request) {
		w.WriteHeader(204)
	})

	ts := httptest.NewServer(TimeoutHandler(delay204, time.Nanosecond, ""))
	defer ts.Close()

	var wg sync.WaitGroup
	gate := make(chan bool, 50)
	n := 500
	if testing.Short() {
		n = 10
	}
	for i := 0; i < n; i++ {
		gate <- true
		wg.Add(1)
		go func() {
			defer wg.Done()
			defer func() { <-gate }()
			res, err := Get(ts.URL)
			if err != nil {
				t.Error(err)
				return
			}
			defer res.Body.Close()
			io.Copy(ioutil.Discard, res.Body)
		}()
	}
	wg.Wait()
}

// Verifies we don't path.Clean() on the wrong parts in redirects.
func TestRedirectMunging(t *testing.T) {
	req, _ := NewRequest("GET", "http://example.com/", nil)

	resp := httptest.NewRecorder()
	Redirect(resp, req, "/foo?next=http://bar.com/", 302)
	if g, e := resp.Header().Get("Location"), "/foo?next=http://bar.com/"; g != e {
		t.Errorf("Location header was %q; want %q", g, e)
	}

	resp = httptest.NewRecorder()
	Redirect(resp, req, "http://localhost:8080/_ah/login?continue=http://localhost:8080/", 302)
	if g, e := resp.Header().Get("Location"), "http://localhost:8080/_ah/login?continue=http://localhost:8080/"; g != e {
		t.Errorf("Location header was %q; want %q", g, e)
	}
}

func TestRedirectBadPath(t *testing.T) {
	// This used to crash. It's not valid input (bad path), but it
	// shouldn't crash.
	rr := httptest.NewRecorder()
	req := &Request{
		Method: "GET",
		URL: &url.URL{
			Scheme: "http",
			Path:   "not-empty-but-no-leading-slash", // bogus
		},
	}
	Redirect(rr, req, "", 304)
	if rr.Code != 304 {
		t.Errorf("Code = %d; want 304", rr.Code)
	}
}

// TestZeroLengthPostAndResponse exercises an optimization done by the Transport:
// when there is no body (either because the method doesn't permit a body, or an
// explicit Content-Length of zero is present), then the transport can re-use the
// connection immediately. But when it re-uses the connection, it typically closes
// the previous request's body, which is not optimal for zero-lengthed bodies,
// as the client would then see http.ErrBodyReadAfterClose and not 0, io.EOF.
func TestZeroLengthPostAndResponse(t *testing.T) {
	defer afterTest(t)
	ts := httptest.NewServer(HandlerFunc(func(rw ResponseWriter, r *Request) {
		all, err := ioutil.ReadAll(r.Body)
		if err != nil {
			t.Fatalf("handler ReadAll: %v", err)
		}
		if len(all) != 0 {
			t.Errorf("handler got %d bytes; expected 0", len(all))
		}
		rw.Header().Set("Content-Length", "0")
	}))
	defer ts.Close()

	req, err := NewRequest("POST", ts.URL, strings.NewReader(""))
	if err != nil {
		t.Fatal(err)
	}
	req.ContentLength = 0

	var resp [5]*Response
	for i := range resp {
		resp[i], err = DefaultClient.Do(req)
		if err != nil {
			t.Fatalf("client post #%d: %v", i, err)
		}
	}

	for i := range resp {
		all, err := ioutil.ReadAll(resp[i].Body)
		if err != nil {
			t.Fatalf("req #%d: client ReadAll: %v", i, err)
		}
		if len(all) != 0 {
			t.Errorf("req #%d: client got %d bytes; expected 0", i, len(all))
		}
	}
}

func TestHandlerPanicNil(t *testing.T) {
	testHandlerPanic(t, false, nil)
}

func TestHandlerPanic(t *testing.T) {
	testHandlerPanic(t, false, "intentional death for testing")
}

func TestHandlerPanicWithHijack(t *testing.T) {
	testHandlerPanic(t, true, "intentional death for testing")
}

func testHandlerPanic(t *testing.T, withHijack bool, panicValue interface{}) {
	defer afterTest(t)
	// Unlike the other tests that set the log output to ioutil.Discard
	// to quiet the output, this test uses a pipe.  The pipe serves three
	// purposes:
	//
	//   1) The log.Print from the http server (generated by the caught
	//      panic) will go to the pipe instead of stderr, making the
	//      output quiet.
	//
	//   2) We read from the pipe to verify that the handler
	//      actually caught the panic and logged something.
	//
	//   3) The blocking Read call prevents this TestHandlerPanic
	//      function from exiting before the HTTP server handler
	//      finishes crashing. If this text function exited too
	//      early (and its defer log.SetOutput(os.Stderr) ran),
	//      then the crash output could spill into the next test.
	pr, pw := io.Pipe()
	log.SetOutput(pw)
	defer log.SetOutput(os.Stderr)
	defer pw.Close()

	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		if withHijack {
			rwc, _, err := w.(Hijacker).Hijack()
			if err != nil {
				t.Logf("unexpected error: %v", err)
			}
			defer rwc.Close()
		}
		panic(panicValue)
	}))
	defer ts.Close()

	// Do a blocking read on the log output pipe so its logging
	// doesn't bleed into the next test.  But wait only 5 seconds
	// for it.
	done := make(chan bool, 1)
	go func() {
		buf := make([]byte, 4<<10)
		_, err := pr.Read(buf)
		pr.Close()
		if err != nil && err != io.EOF {
			t.Error(err)
		}
		done <- true
	}()

	_, err := Get(ts.URL)
	if err == nil {
		t.Logf("expected an error")
	}

	if panicValue == nil {
		return
	}

	select {
	case <-done:
		return
	case <-time.After(5 * time.Second):
		t.Fatal("expected server handler to log an error")
	}
}

func TestServerNoDate(t *testing.T)        { testServerNoHeader(t, "Date") }
func TestServerNoContentType(t *testing.T) { testServerNoHeader(t, "Content-Type") }

func testServerNoHeader(t *testing.T, header string) {
	defer afterTest(t)
	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		w.Header()[header] = nil
		io.WriteString(w, "<html>foo</html>") // non-empty
	}))
	defer ts.Close()
	res, err := Get(ts.URL)
	if err != nil {
		t.Fatal(err)
	}
	res.Body.Close()
	if got, ok := res.Header[header]; ok {
		t.Fatalf("Expected no %s header; got %q", header, got)
	}
}

func TestStripPrefix(t *testing.T) {
	defer afterTest(t)
	h := HandlerFunc(func(w ResponseWriter, r *Request) {
		w.Header().Set("X-Path", r.URL.Path)
	})
	ts := httptest.NewServer(StripPrefix("/foo", h))
	defer ts.Close()

	res, err := Get(ts.URL + "/foo/bar")
	if err != nil {
		t.Fatal(err)
	}
	if g, e := res.Header.Get("X-Path"), "/bar"; g != e {
		t.Errorf("test 1: got %s, want %s", g, e)
	}
	res.Body.Close()

	res, err = Get(ts.URL + "/bar")
	if err != nil {
		t.Fatal(err)
	}
	if g, e := res.StatusCode, 404; g != e {
		t.Errorf("test 2: got status %v, want %v", g, e)
	}
	res.Body.Close()
}

func TestRequestLimit(t *testing.T) {
	defer afterTest(t)
	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
		t.Fatalf("didn't expect to get request in Handler")
	}))
	defer ts.Close()
	req, _ := NewRequest("GET", ts.URL, nil)
	var b…