cmd/vendor/.../pprof: update to 0f7d9ba1

In particular, to pull a few fixes that were causing some tests to be
flaky on our build dashboard.

Fixes #24405.
Fixes #24508.
Fixes #24611.

Change-Id: I713156ad11c924e4a4b603144d10395523d526ed
Reviewed-on: https://go-review.googlesource.com/105275
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

10 files changed, 156 insertions, 161 deletions

diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go
index c2b1cd082b..3b7439fc9a 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go
@@ -54,7 +54,7 @@ func PProf(eo *plugin.Options) error {
 	}
 
 	if src.HTTPHostport != "" {
-		return serveWebInterface(src.HTTPHostport, p, o, true)
+		return serveWebInterface(src.HTTPHostport, p, o)
 	}
 	return interactive(p, o)
 }
@@ -138,7 +138,7 @@ func generateReport(p *profile.Profile, cmd []string, vars variables, o *plugin.
 
 	// Output to specified file.
 	o.UI.PrintErr("Generating report in ", output)
-	out, err := os.Create(output)
+	out, err := o.Writer.Open(output)
 	if err != nil {
 		return err
 	}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/driver_test.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver_test.go
index 0604da911c..06219eae64 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/driver_test.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver_test.go
@@ -96,114 +96,118 @@ func TestParse(t *testing.T) {
 	baseVars := pprofVariables
 	defer func() { pprofVariables = baseVars }()
 	for _, tc := range testcase {
-		// Reset the pprof variables before processing
-		pprofVariables = baseVars.makeCopy()
+		t.Run(tc.flags+":"+tc.source, func(t *testing.T) {
+			// Reset the pprof variables before processing
+			pprofVariables = baseVars.makeCopy()
 
-		f := baseFlags()
-		f.args = []string{tc.source}
+			testUI := &proftest.TestUI{T: t, AllowRx: "Generating report in|Ignoring local file|expression matched no samples|Interpreted .* as range, not regexp"}
 
-		flags := strings.Split(tc.flags, ",")
+			f := baseFlags()
+			f.args = []string{tc.source}
 
-		// Skip the output format in the first flag, to output to a proto
-		addFlags(&f, flags[1:])
+			flags := strings.Split(tc.flags, ",")
 
-		// Encode profile into a protobuf and decode it again.
-		protoTempFile, err := ioutil.TempFile("", "profile_proto")
-		if err != nil {
-			t.Errorf("cannot create tempfile: %v", err)
-		}
-		defer os.Remove(protoTempFile.Name())
-		defer protoTempFile.Close()
-		f.strings["output"] = protoTempFile.Name()
-
-		if flags[0] == "topproto" {
-			f.bools["proto"] = false
-			f.bools["topproto"] = true
-		}
+			// Skip the output format in the first flag, to output to a proto
+			addFlags(&f, flags[1:])
 
-		// First pprof invocation to save the profile into a profile.proto.
-		o1 := setDefaults(nil)
-		o1.Flagset = f
-		o1.Fetch = testFetcher{}
-		o1.Sym = testSymbolizer{}
-		if err := PProf(o1); err != nil {
-			t.Errorf("%s %q:  %v", tc.source, tc.flags, err)
-			continue
-		}
-		// Reset the pprof variables after the proto invocation
-		pprofVariables = baseVars.makeCopy()
+			// Encode profile into a protobuf and decode it again.
+			protoTempFile, err := ioutil.TempFile("", "profile_proto")
+			if err != nil {
+				t.Errorf("cannot create tempfile: %v", err)
+			}
+			defer os.Remove(protoTempFile.Name())
+			defer protoTempFile.Close()
+			f.strings["output"] = protoTempFile.Name()
 
-		// Read the profile from the encoded protobuf
-		outputTempFile, err := ioutil.TempFile("", "profile_output")
-		if err != nil {
-			t.Errorf("cannot create tempfile: %v", err)
-		}
-		defer os.Remove(outputTempFile.Name())
-		defer outputTempFile.Close()
-		f.strings["output"] = outputTempFile.Name()
-		f.args = []string{protoTempFile.Name()}
+			if flags[0] == "topproto" {
+				f.bools["proto"] = false
+				f.bools["topproto"] = true
+			}
 
-		var solution string
-		// Apply the flags for the second pprof run, and identify name of
-		// the file containing expected results
-		if flags[0] == "topproto" {
-			solution = solutionFilename(tc.source, &f)
-			delete(f.bools, "topproto")
-			f.bools["text"] = true
-		} else {
-			delete(f.bools, "proto")
-			addFlags(&f, flags[:1])
-			solution = solutionFilename(tc.source, &f)
-		}
-		// The add_comment flag is not idempotent so only apply it on the first run.
-		delete(f.strings, "add_comment")
+			// First pprof invocation to save the profile into a profile.proto.
+			o1 := setDefaults(nil)
+			o1.Flagset = f
+			o1.Fetch = testFetcher{}
+			o1.Sym = testSymbolizer{}
+			o1.UI = testUI
+			if err := PProf(o1); err != nil {
+				t.Fatalf("%s %q:  %v", tc.source, tc.flags, err)
+			}
+			// Reset the pprof variables after the proto invocation
+			pprofVariables = baseVars.makeCopy()
 
-		// Second pprof invocation to read the profile from profile.proto
-		// and generate a report.
-		o2 := setDefaults(nil)
-		o2.Flagset = f
-		o2.Sym = testSymbolizeDemangler{}
-		o2.Obj = new(mockObjTool)
+			// Read the profile from the encoded protobuf
+			outputTempFile, err := ioutil.TempFile("", "profile_output")
+			if err != nil {
+				t.Errorf("cannot create tempfile: %v", err)
+			}
+			defer os.Remove(outputTempFile.Name())
+			defer outputTempFile.Close()
+			f.strings["output"] = outputTempFile.Name()
+			f.args = []string{protoTempFile.Name()}
 
-		if err := PProf(o2); err != nil {
-			t.Errorf("%s: %v", tc.source, err)
-		}
-		b, err := ioutil.ReadFile(outputTempFile.Name())
-		if err != nil {
-			t.Errorf("Failed to read profile %s: %v", outputTempFile.Name(), err)
-		}
+			var solution string
+			// Apply the flags for the second pprof run, and identify name of
+			// the file containing expected results
+			if flags[0] == "topproto" {
+				solution = solutionFilename(tc.source, &f)
+				delete(f.bools, "topproto")
+				f.bools["text"] = true
+			} else {
+				delete(f.bools, "proto")
+				addFlags(&f, flags[:1])
+				solution = solutionFilename(tc.source, &f)
+			}
+			// The add_comment flag is not idempotent so only apply it on the first run.
+			delete(f.strings, "add_comment")
 
-		// Read data file with expected solution
-		solution = "testdata/" + solution
-		sbuf, err := ioutil.ReadFile(solution)
-		if err != nil {
-			t.Errorf("reading solution file %s: %v", solution, err)
-			continue
-		}
-		if runtime.GOOS == "windows" {
-			sbuf = bytes.Replace(sbuf, []byte("testdata/"), []byte("testdata\\"), -1)
-			sbuf = bytes.Replace(sbuf, []byte("/path/to/"), []byte("\\path\\to\\"), -1)
-		}
+			// Second pprof invocation to read the profile from profile.proto
+			// and generate a report.
+			o2 := setDefaults(nil)
+			o2.Flagset = f
+			o2.Sym = testSymbolizeDemangler{}
+			o2.Obj = new(mockObjTool)
+			o2.UI = testUI
 
-		if flags[0] == "svg" {
-			b = removeScripts(b)
-			sbuf = removeScripts(sbuf)
-		}
+			if err := PProf(o2); err != nil {
+				t.Errorf("%s: %v", tc.source, err)
+			}
+			b, err := ioutil.ReadFile(outputTempFile.Name())
+			if err != nil {
+				t.Errorf("Failed to read profile %s: %v", outputTempFile.Name(), err)
+			}
 
-		if string(b) != string(sbuf) {
-			t.Errorf("diff %s %s", solution, tc.source)
-			d, err := proftest.Diff(sbuf, b)
+			// Read data file with expected solution
+			solution = "testdata/" + solution
+			sbuf, err := ioutil.ReadFile(solution)
 			if err != nil {
-				t.Fatalf("diff %s %v", solution, err)
+				t.Fatalf("reading solution file %s: %v", solution, err)
 			}
-			t.Errorf("%s\n%s\n", solution, d)
-			if *updateFlag {
-				err := ioutil.WriteFile(solution, b, 0644)
+			if runtime.GOOS == "windows" {
+				sbuf = bytes.Replace(sbuf, []byte("testdata/"), []byte("testdata\\"), -1)
+				sbuf = bytes.Replace(sbuf, []byte("/path/to/"), []byte("\\path\\to\\"), -1)
+			}
+
+			if flags[0] == "svg" {
+				b = removeScripts(b)
+				sbuf = removeScripts(sbuf)
+			}
+
+			if string(b) != string(sbuf) {
+				t.Errorf("diff %s %s", solution, tc.source)
+				d, err := proftest.Diff(sbuf, b)
 				if err != nil {
-					t.Errorf("failed to update the solution file %q: %v", solution, err)
+					t.Fatalf("diff %s %v", solution, err)
+				}
+				t.Errorf("%s\n%s\n", solution, d)
+				if *updateFlag {
+					err := ioutil.WriteFile(solution, b, 0644)
+					if err != nil {
+						t.Errorf("failed to update the solution file %q: %v", solution, err)
+					}
 				}
 			}
-		}
+		})
 	}
 }
 
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch.go
index a929b0f790..1b34e70bea 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch.go
@@ -407,6 +407,7 @@ mapping:
 				if matches, err := filepath.Glob(filepath.Join(path, m.BuildID, "*")); err == nil {
 					fileNames = append(fileNames, matches...)
 				}
+				fileNames = append(fileNames, filepath.Join(path, m.File, m.BuildID)) // perf path format
 			}
 			if m.File != "" {
 				// Try both the basename and the full path, to support the same directory
@@ -534,7 +535,8 @@ func convertPerfData(perfPath string, ui plugin.UI) (*os.File, error) {
 		return nil, err
 	}
 	deferDeleteTempFile(profile.Name())
-	cmd := exec.Command("perf_to_profile", perfPath, profile.Name())
+	cmd := exec.Command("perf_to_profile", "-i", perfPath, "-o", profile.Name(), "-f")
+	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
 	if err := cmd.Run(); err != nil {
 		profile.Close()
 		return nil, fmt.Errorf("failed to convert perf.data file. Try github.com/google/perf_data_converter: %v", err)
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go
index c80a0dbc1d..f15328bfae 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch_test.go
@@ -283,8 +283,10 @@ func TestFetchWithBase(t *testing.T) {
 			}
 			f.args = tc.sources
 
-			o := setDefaults(nil)
-			o.Flagset = f
+			o := setDefaults(&plugin.Options{
+				UI:      &proftest.TestUI{T: t, AllowRx: "Local symbolization failed|Some binary filenames not available"},
+				Flagset: f,
+			})
 			src, _, err := parseFlags(o)
 
 			if err != nil {
@@ -397,18 +399,6 @@ func TestHttpsInsecure(t *testing.T) {
 	}()
 	defer l.Close()
 
-	go func() {
-		deadline := time.Now().Add(5 * time.Second)
-		for time.Now().Before(deadline) {
-			// Simulate a hotspot function. Spin in the inner loop for 100M iterations
-			// to ensure we get most of the samples landed here rather than in the
-			// library calls. We assume Go compiler won't elide the empty loop.
-			for i := 0; i < 1e8; i++ {
-			}
-			runtime.Gosched()
-		}
-	}()
-
 	outputTempFile, err := ioutil.TempFile("", "profile_output")
 	if err != nil {
 		t.Fatalf("Failed to create tempfile: %v", err)
@@ -416,7 +406,7 @@ func TestHttpsInsecure(t *testing.T) {
 	defer os.Remove(outputTempFile.Name())
 	defer outputTempFile.Close()
 
-	address := "https+insecure://" + l.Addr().String() + "/debug/pprof/profile"
+	address := "https+insecure://" + l.Addr().String() + "/debug/pprof/goroutine"
 	s := &source{
 		Sources:   []string{address},
 		Seconds:   10,
@@ -435,31 +425,14 @@ func TestHttpsInsecure(t *testing.T) {
 	if len(p.SampleType) == 0 {
 		t.Fatalf("fetchProfiles(%s) got empty profile: len(p.SampleType)==0", address)
 	}
-	switch runtime.GOOS {
-	case "plan9":
-		// CPU profiling is not supported on Plan9; see golang.org/issues/22564.
-		return
-	case "darwin":
-		if runtime.GOARCH == "arm" || runtime.GOARCH == "arm64" {
-			// CPU profiling on iOS os not symbolized; see golang.org/issues/22612.
-			return
-		}
-	}
 	if len(p.Function) == 0 {
 		t.Fatalf("fetchProfiles(%s) got non-symbolized profile: len(p.Function)==0", address)
 	}
-	if err := checkProfileHasFunction(p, "TestHttpsInsecure"); !badSigprofOS[runtime.GOOS] && err != nil {
+	if err := checkProfileHasFunction(p, "TestHttpsInsecure"); err != nil {
 		t.Fatalf("fetchProfiles(%s) %v", address, err)
 	}
 }
 
-// Some operating systems don't trigger the profiling signal right.
-// See https://github.com/golang/go/issues/13841.
-var badSigprofOS = map[string]bool{
-	"darwin": true,
-	"netbsd": true,
-}
-
 func checkProfileHasFunction(p *profile.Profile, fname string) error {
 	for _, f := range p.Function {
 		if strings.Contains(f.Name, fname) {
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go
index 10588d6262..29a41011bb 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go
@@ -92,7 +92,7 @@ func (ui *webInterface) flamegraph(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	ui.render(w, "/flamegraph", "flamegraph", rpt, errList, config.Labels, webArgs{
+	ui.render(w, "flamegraph", rpt, errList, config.Labels, webArgs{
 		FlameGraph: template.JS(b),
 		Nodes:      nodeArr,
 	})
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go
index b893697b62..bebfbbec1e 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go
@@ -149,9 +149,14 @@ func greetings(p *profile.Profile, ui plugin.UI) {
 	numLabelUnits := identifyNumLabelUnits(p, ui)
 	ropt, err := reportOptions(p, numLabelUnits, pprofVariables)
 	if err == nil {
-		ui.Print(strings.Join(report.ProfileLabels(report.New(p, ropt)), "\n"))
+		rpt := report.New(p, ropt)
+		ui.Print(strings.Join(report.ProfileLabels(rpt), "\n"))
+		if rpt.Total() == 0 && len(p.SampleType) > 1 {
+			ui.Print(`No samples were found with the default sample value type.`)
+			ui.Print(`Try "sample_index" command to analyze different sample values.`, "\n")
+		}
 	}
-	ui.Print("Entering interactive mode (type \"help\" for commands, \"o\" for options)")
+	ui.Print(`Entering interactive mode (type "help" for commands, "o" for options)`)
 }
 
 // shortcuts represents composite commands that expand into a sequence
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/options.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/options.go
index cb20e948b4..34167d4bf5 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/options.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/options.go
@@ -128,6 +128,10 @@ func (ui *stdUI) IsTerminal() bool {
 	return false
 }
 
+func (ui *stdUI) WantBrowser() bool {
+	return true
+}
+
 func (ui *stdUI) SetAutoComplete(func(string) string) {
 }
 
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
index 5d2821cd42..e9bc872035 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
@@ -233,7 +233,7 @@ table tr td {
 {{define "header"}}
 <div class="header">
   <div class="title">
-    <h1><a href="/">pprof</a></h1>
+    <h1><a href="./">pprof</a></h1>
   </div>
 
   <div id="view" class="menu-item">
@@ -242,12 +242,12 @@ table tr td {
       <i class="downArrow"></i>
     </div>
     <div class="submenu">
-      <a title="{{.Help.top}}"  href="/top" id="topbtn">Top</a>
-      <a title="{{.Help.graph}}" href="/" id="graphbtn">Graph</a>
-      <a title="{{.Help.flamegraph}}" href="/flamegraph" id="flamegraph">Flame Graph</a>
-      <a title="{{.Help.peek}}" href="/peek" id="peek">Peek</a>
-      <a title="{{.Help.list}}" href="/source" id="list">Source</a>
-      <a title="{{.Help.disasm}}" href="/disasm" id="disasm">Disassemble</a>
+      <a title="{{.Help.top}}"  href="./top" id="topbtn">Top</a>
+      <a title="{{.Help.graph}}" href="./" id="graphbtn">Graph</a>
+      <a title="{{.Help.flamegraph}}" href="./flamegraph" id="flamegraph">Flame Graph</a>
+      <a title="{{.Help.peek}}" href="./peek" id="peek">Peek</a>
+      <a title="{{.Help.list}}" href="./source" id="list">Source</a>
+      <a title="{{.Help.disasm}}" href="./disasm" id="disasm">Disassemble</a>
     </div>
   </div>
 
@@ -257,12 +257,12 @@ table tr td {
       <i class="downArrow"></i>
     </div>
     <div class="submenu">
-      <a title="{{.Help.focus}}" href="{{.BaseURL}}" id="focus">Focus</a>
-      <a title="{{.Help.ignore}}" href="{{.BaseURL}}" id="ignore">Ignore</a>
-      <a title="{{.Help.hide}}" href="{{.BaseURL}}" id="hide">Hide</a>
-      <a title="{{.Help.show}}" href="{{.BaseURL}}" id="show">Show</a>
+      <a title="{{.Help.focus}}" href="?" id="focus">Focus</a>
+      <a title="{{.Help.ignore}}" href="?" id="ignore">Ignore</a>
+      <a title="{{.Help.hide}}" href="?" id="hide">Hide</a>
+      <a title="{{.Help.show}}" href="?" id="show">Show</a>
       <hr>
-      <a title="{{.Help.reset}}" href="{{.BaseURL}}">Reset</a>
+      <a title="{{.Help.reset}}" href="?">Reset</a>
     </div>
   </div>
 
@@ -295,7 +295,7 @@ table tr td {
     {{.HTMLBody}}
   </div>
   {{template "script" .}}
-  <script>viewer({{.BaseURL}}, {{.Nodes}});</script>
+  <script>viewer(new URL(window.location.href), {{.Nodes}});</script>
 </body>
 </html>
 {{end}}
@@ -597,7 +597,7 @@ function viewer(baseUrl, nodes) {
   function handleKey(e) {
     if (e.keyCode != 13) return;
     window.location.href =
-        updateUrl(new URL({{.BaseURL}}, window.location.href), 'f');
+        updateUrl(new URL(window.location.href), 'f');
     e.preventDefault();
   }
 
@@ -963,7 +963,7 @@ function viewer(baseUrl, nodes) {
       bindSort('namehdr', 'Name');
     }
 
-    viewer({{.BaseURL}}, {{.Nodes}});
+    viewer(new URL(window.location.href), {{.Nodes}});
     makeTopTable({{.Total}}, {{.Top}});
   </script>
 </body>
@@ -986,7 +986,7 @@ function viewer(baseUrl, nodes) {
     {{.HTMLBody}}
   </div>
   {{template "script" .}}
-  <script>viewer({{.BaseURL}}, null);</script>
+  <script>viewer(new URL(window.location.href), null);</script>
 </body>
 </html>
 {{end}}
@@ -1007,7 +1007,7 @@ function viewer(baseUrl, nodes) {
     </pre>
   </div>
   {{template "script" .}}
-  <script>viewer({{.BaseURL}}, null);</script>
+  <script>viewer(new URL(window.location.href), null);</script>
 </body>
 </html>
 {{end}}
@@ -1044,7 +1044,7 @@ function viewer(baseUrl, nodes) {
     <div id="flamegraphdetails" class="flamegraph-details"></div>
   </div>
   {{template "script" .}}
-  <script>viewer({{.BaseURL}}, {{.Nodes}});</script>
+  <script>viewer(new URL(window.location.href), {{.Nodes}});</script>
   <script>{{template "d3script" .}}</script>
   <script>{{template "d3tipscript" .}}</script>
   <script>{{template "d3flamegraphscript" .}}</script>
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
index 20d4e025f4..89bc558668 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
@@ -69,7 +69,6 @@ func (ec *errorCatcher) PrintErr(args ...interface{}) {
 
 // webArgs contains arguments passed to templates in webhtml.go.
 type webArgs struct {
-	BaseURL    string
 	Title      string
 	Errors     []string
 	Total      int64
@@ -82,7 +81,7 @@ type webArgs struct {
 	FlameGraph template.JS
 }
 
-func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, wantBrowser bool) error {
+func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options) error {
 	host, port, err := getHostAndPort(hostport)
 	if err != nil {
 		return err
@@ -117,7 +116,7 @@ func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, w
 		},
 	}
 
-	if wantBrowser {
+	if o.UI.WantBrowser() {
 		go openBrowser("http://"+args.Hostport, o)
 	}
 	return server(args)
@@ -172,7 +171,15 @@ func defaultWebServer(args *plugin.HTTPServerArgs) error {
 		}
 		h.ServeHTTP(w, req)
 	})
-	s := &http.Server{Handler: handler}
+
+	// We serve the ui at /ui/ and redirect there from the root. This is done
+	// to surface any problems with serving the ui at a non-root early. See:
+	//
+	// https://github.com/google/pprof/pull/348
+	mux := http.NewServeMux()
+	mux.Handle("/ui/", http.StripPrefix("/ui", handler))
+	mux.Handle("/", http.RedirectHandler("/ui/", http.StatusTemporaryRedirect))
+	s := &http.Server{Handler: mux}
 	return s.Serve(ln)
 }
 
@@ -248,11 +255,10 @@ func (ui *webInterface) makeReport(w http.ResponseWriter, req *http.Request,
 }
 
 // render generates html using the named template based on the contents of data.
-func (ui *webInterface) render(w http.ResponseWriter, baseURL, tmpl string,
+func (ui *webInterface) render(w http.ResponseWriter, tmpl string,
 	rpt *report.Report, errList, legend []string, data webArgs) {
 	file := getFromLegend(legend, "File: ", "unknown")
 	profile := getFromLegend(legend, "Type: ", "unknown")
-	data.BaseURL = baseURL
 	data.Title = file + " " + profile
 	data.Errors = errList
 	data.Total = rpt.Total()
@@ -297,7 +303,7 @@ func (ui *webInterface) dot(w http.ResponseWriter, req *http.Request) {
 		nodes = append(nodes, n.Info.Name)
 	}
 
-	ui.render(w, "/", "graph", rpt, errList, legend, webArgs{
+	ui.render(w, "graph", rpt, errList, legend, webArgs{
 		HTMLBody: template.HTML(string(svg)),
 		Nodes:    nodes,
 	})
@@ -332,7 +338,7 @@ func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
 		nodes = append(nodes, item.Name)
 	}
 
-	ui.render(w, "/top", "top", rpt, errList, legend, webArgs{
+	ui.render(w, "top", rpt, errList, legend, webArgs{
 		Top:   top,
 		Nodes: nodes,
 	})
@@ -354,7 +360,7 @@ func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
 	}
 
 	legend := report.ProfileLabels(rpt)
-	ui.render(w, "/disasm", "plaintext", rpt, errList, legend, webArgs{
+	ui.render(w, "plaintext", rpt, errList, legend, webArgs{
 		TextBody: out.String(),
 	})
 
@@ -378,7 +384,7 @@ func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
 	}
 
 	legend := report.ProfileLabels(rpt)
-	ui.render(w, "/source", "sourcelisting", rpt, errList, legend, webArgs{
+	ui.render(w, "sourcelisting", rpt, errList, legend, webArgs{
 		HTMLBody: template.HTML(body.String()),
 	})
 }
@@ -399,7 +405,7 @@ func (ui *webInterface) peek(w http.ResponseWriter, req *http.Request) {
 	}
 
 	legend := report.ProfileLabels(rpt)
-	ui.render(w, "/peek", "plaintext", rpt, errList, legend, webArgs{
+	ui.render(w, "plaintext", rpt, errList, legend, webArgs{
 		TextBody: out.String(),
 	})
 }
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go
index 424752fd1f..7e061699ce 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui_test.go
@@ -28,6 +28,7 @@ import (
 	"testing"
 
 	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/internal/proftest"
 	"github.com/google/pprof/profile"
 )
 
@@ -55,9 +56,9 @@ func TestWebInterface(t *testing.T) {
 	// Start server and wait for it to be initialized
 	go serveWebInterface("unused:1234", prof, &plugin.Options{
 		Obj:        fakeObjTool{},
-		UI:         &stdUI{},
+		UI:         &proftest.TestUI{},
 		HTTPServer: creator,
-	}, false)
+	})
 	<-serverCreated
 	defer server.Close()