libgo: update to Go 1.8.1 release

    
    Reviewed-on: https://go-review.googlesource.com/40775

From-SVN: r246957

2 files changed, 37 insertions, 4 deletions

diff --git a/libgo/go/text/template/multi_test.go b/libgo/go/text/template/multi_test.go
index 8142f00..5d8c08f 100644
--- a/libgo/go/text/template/multi_test.go
+++ b/libgo/go/text/template/multi_test.go
@@ -363,7 +363,7 @@ func TestEmptyTemplate(t *testing.T) {
 		{[]string{"{{.}}", ""}, "twice", ""},
 	}
 
-	for _, c := range cases {
+	for i, c := range cases {
 		root := New("root")
 
 		var (
@@ -378,10 +378,43 @@ func TestEmptyTemplate(t *testing.T) {
 		}
 		buf := &bytes.Buffer{}
 		if err := m.Execute(buf, c.in); err != nil {
-			t.Fatal(err)
+			t.Error(i, err)
+			continue
 		}
 		if buf.String() != c.want {
 			t.Errorf("expected string %q: got %q", c.want, buf.String())
 		}
 	}
 }
+
+// Issue 19249 was a regression in 1.8 caused by the handling of empty
+// templates added in that release, which got different answers depending
+// on the order templates appeared in the internal map.
+func TestIssue19294(t *testing.T) {
+	// The empty block in "xhtml" should be replaced during execution
+	// by the contents of "stylesheet", but if the internal map associating
+	// names with templates is built in the wrong order, the empty block
+	// looks non-empty and this doesn't happen.
+	var inlined = map[string]string{
+		"stylesheet": `{{define "stylesheet"}}stylesheet{{end}}`,
+		"xhtml":      `{{block "stylesheet" .}}{{end}}`,
+	}
+	all := []string{"stylesheet", "xhtml"}
+	for i := 0; i < 100; i++ {
+		res, err := New("title.xhtml").Parse(`{{template "xhtml" .}}`)
+		if err != nil {
+			t.Fatal(err)
+		}
+		for _, name := range all {
+			_, err := res.New(name).Parse(inlined[name])
+			if err != nil {
+				t.Fatal(err)
+			}
+		}
+		var buf bytes.Buffer
+		res.Execute(&buf, 0)
+		if buf.String() != "stylesheet" {
+			t.Fatalf("iteration %d: got %q; expected %q", i, buf.String(), "stylesheet")
+		}
+	}
+}
diff --git a/libgo/go/text/template/template.go b/libgo/go/text/template/template.go
index b6fceb1..3b4f34b 100644
--- a/libgo/go/text/template/template.go
+++ b/libgo/go/text/template/template.go
@@ -127,7 +127,7 @@ func (t *Template) AddParseTree(name string, tree *parse.Tree) (*Template, error
 	// Even if nt == t, we need to install it in the common.tmpl map.
 	if replace, err := t.associate(nt, tree); err != nil {
 		return nil, err
-	} else if replace {
+	} else if replace || nt.Tree == nil {
 		nt.Tree = tree
 	}
 	return nt, nil
@@ -215,7 +215,7 @@ func (t *Template) associate(new *Template, tree *parse.Tree) (bool, error) {
 	if new.common != t.common {
 		panic("internal error: associate not common")
 	}
-	if t.tmpl[new.name] != nil && parse.IsEmptyTree(tree.Root) && t.Tree != nil {
+	if old := t.tmpl[new.name]; old != nil && parse.IsEmptyTree(tree.Root) && old.Tree != nil {
 		// If a template by that name exists,
 		// don't replace it with an empty template.
 		return false, nil