libgo: update to Go1.10beta1

    
    Update the Go library to the 1.10beta1 release.
    
    Requires a few changes to the compiler for modifications to the map
    runtime code, and to handle some nowritebarrier cases in the runtime.
    
    Reviewed-on: https://go-review.googlesource.com/86455

gotools/:
	* Makefile.am (go_cmd_vet_files): New variable.
	(go_cmd_buildid_files, go_cmd_test2json_files): New variables.
	(s-zdefaultcc): Change from constants to functions.
	(noinst_PROGRAMS): Add vet, buildid, and test2json.
	(cgo$(EXEEXT)): Link against $(LIBGOTOOL).
	(vet$(EXEEXT)): New target.
	(buildid$(EXEEXT)): New target.
	(test2json$(EXEEXT)): New target.
	(install-exec-local): Install all $(noinst_PROGRAMS).
	(uninstall-local): Uninstasll all $(noinst_PROGRAMS).
	(check-go-tool): Depend on $(noinst_PROGRAMS).  Copy down
	objabi.go.
	(check-runtime): Depend on $(noinst_PROGRAMS).
	(check-cgo-test, check-carchive-test): Likewise.
	(check-vet): New target.
	(check): Depend on check-vet.  Look at cmd_vet-testlog.
	(.PHONY): Add check-vet.
	* Makefile.in: Rebuild.

From-SVN: r256365

4 files changed, 44 insertions, 6 deletions

diff --git a/libgo/go/html/entity.go b/libgo/go/html/entity.go
index af8a007..dfeaf6c 100644
--- a/libgo/go/html/entity.go
+++ b/libgo/go/html/entity.go
@@ -8,7 +8,7 @@ package html
 const longestEntityWithoutSemicolon = 6
 
 // entity is a map from HTML entity names to their values. The semicolon matters:
-// http://www.whatwg.org/specs/web-apps/current-work/multipage/named-character-references.html
+// https://html.spec.whatwg.org/multipage/named-characters.html
 // lists both "amp" and "amp;" as two separate entries.
 //
 // Note that the HTML5 list is larger than the HTML4 list at
diff --git a/libgo/go/html/template/escape_test.go b/libgo/go/html/template/escape_test.go
index f5a4ce1..92f12ca 100644
--- a/libgo/go/html/template/escape_test.go
+++ b/libgo/go/html/template/escape_test.go
@@ -1840,7 +1840,7 @@ func TestErrorOnUndefined(t *testing.T) {
 
 	err := tmpl.Execute(nil, nil)
 	if err == nil {
-		t.Error("expected error")
+		t.Fatal("expected error")
 	}
 	if !strings.Contains(err.Error(), "incomplete") {
 		t.Errorf("expected error about incomplete template; got %s", err)
@@ -1860,10 +1860,10 @@ func TestIdempotentExecute(t *testing.T) {
 	for i := 0; i < 2; i++ {
 		err = tmpl.ExecuteTemplate(got, "hello", nil)
 		if err != nil {
-			t.Errorf("unexpected error: %s", err)
+			t.Fatalf("unexpected error: %s", err)
 		}
 		if got.String() != want {
-			t.Errorf("after executing template \"hello\", got:\n\t%q\nwant:\n\t%q\n", got.String(), want)
+			t.Fatalf("after executing template \"hello\", got:\n\t%q\nwant:\n\t%q\n", got.String(), want)
 		}
 		got.Reset()
 	}
@@ -1871,7 +1871,7 @@ func TestIdempotentExecute(t *testing.T) {
 	// "main" does not cause the output of "hello" to change.
 	err = tmpl.ExecuteTemplate(got, "main", nil)
 	if err != nil {
-		t.Errorf("unexpected error: %s", err)
+		t.Fatalf("unexpected error: %s", err)
 	}
 	// If the HTML escaper is added again to the action {{"Ladies & Gentlemen!"}},
 	// we would expected to see the ampersand overescaped to "&amp;amp;".
@@ -1881,6 +1881,19 @@ func TestIdempotentExecute(t *testing.T) {
 	}
 }
 
+// This covers issue #21844.
+func TestAddExistingTreeError(t *testing.T) {
+	tmpl := Must(New("foo").Parse(`<p>{{.}}</p>`))
+	tmpl, err := tmpl.AddParseTree("bar", tmpl.Tree)
+	if err == nil {
+		t.Fatalf("expected error after AddParseTree")
+	}
+	const want = `html/template: cannot add parse tree that template "foo" already references`
+	if got := err.Error(); got != want {
+		t.Errorf("got error:\n\t%q\nwant:\n\t%q\n", got, want)
+	}
+}
+
 func BenchmarkEscapedExecute(b *testing.B) {
 	tmpl := Must(New("t").Parse(`<a onclick="alert('{{.}}')">{{.}}</a>`))
 	var buf bytes.Buffer
diff --git a/libgo/go/html/template/template.go b/libgo/go/html/template/template.go
index 6a661bf..d77aa3d 100644
--- a/libgo/go/html/template/template.go
+++ b/libgo/go/html/template/template.go
@@ -219,6 +219,11 @@ func (t *Template) AddParseTree(name string, tree *parse.Tree) (*Template, error
 
 	t.nameSpace.mu.Lock()
 	defer t.nameSpace.mu.Unlock()
+	for _, tmpl := range t.set {
+		if tmpl.Tree == tree {
+			return nil, fmt.Errorf("html/template: cannot add parse tree that template %q already references", tmpl.Name())
+		}
+	}
 	text, err := t.text.AddParseTree(name, tree)
 	if err != nil {
 		return nil, err
diff --git a/libgo/go/html/template/url.go b/libgo/go/html/template/url.go
index 02123b2..a0bfe76 100644
--- a/libgo/go/html/template/url.go
+++ b/libgo/go/html/template/url.go
@@ -10,8 +10,28 @@ import (
 	"strings"
 )
 
-// urlFilter returns its input unless it contains an unsafe protocol in which
+// urlFilter returns its input unless it contains an unsafe scheme in which
 // case it defangs the entire URL.
+//
+// Schemes that cause unintended side effects that are irreversible without user
+// interaction are considered unsafe. For example, clicking on a "javascript:"
+// link can immediately trigger JavaScript code execution.
+//
+// This filter conservatively assumes that all schemes other than the following
+// are unsafe:
+//    * http:   Navigates to a new website, and may open a new window or tab.
+//              These side effects can be reversed by navigating back to the
+//              previous website, or closing the window or tab. No irreversible
+//              changes will take place without further user interaction with
+//              the new website.
+//    * https:  Same as http.
+//    * mailto: Opens an email program and starts a new draft. This side effect
+//              is not irreversible until the user explicitly clicks send; it
+//              can be undone by closing the email program.
+//
+// To allow URLs containing other schemes to bypass this filter, developers must
+// explicitly indicate that such a URL is expected and safe by encapsulating it
+// in a template.URL value.
 func urlFilter(args ...interface{}) string {
 	s, t := stringify(args...)
 	if t == contentTypeURL {