1 files changed, 19 insertions, 2 deletions
diff --git a/libgo/go/html/template/template.go b/libgo/go/html/template/template.go
index bb9140a..96ab268 100644
--- a/libgo/go/html/template/template.go
+++ b/libgo/go/html/template/template.go
@@ -17,7 +17,7 @@ import (
 // Template is a specialized Template from "text/template" that produces a safe
 // HTML document fragment.
 type Template struct {
-	// Sticky error if escaping fails.
+	// Sticky error if escaping fails, or escapeOK if succeeded.
 	escapeErr error
 	// We could embed the text/template field, but it's safer not to because
 	// we need to keep our version of the name space and the underlying
@@ -80,7 +80,7 @@ func (t *Template) escape() error {
 	defer t.nameSpace.mu.Unlock()
 	if t.escapeErr == nil {
 		if t.Tree == nil {
-			return fmt.Errorf("template: %q is an incomplete or empty template%s", t.Name(), t.text.DefinedTemplates())
+			return fmt.Errorf("template: %q is an incomplete or empty template%s", t.Name(), t.DefinedTemplates())
 		}
 		if err := escapeTemplate(t, t.text.Root, t.Name()); err != nil {
 			return err
@@ -143,6 +143,13 @@ func (t *Template) lookupAndEscapeTemplate(name string) (tmpl *Template, err err
 	return tmpl, err
 }
 
+// DefinedTemplates returns a string listing the defined templates,
+// prefixed by the string "; defined templates are: ". If there are none,
+// it returns the empty string. Used to generate an error message.
+func (t *Template) DefinedTemplates() string {
+	return t.text.DefinedTemplates()
+}
+
 // Parse parses a string into a template. Nested template definitions
 // will be associated with the top-level template t. Parse may be
 // called multiple times to parse definitions of templates to associate
@@ -169,6 +176,8 @@ func (t *Template) Parse(src string) (*Template, error) {
 		tmpl := t.set[name]
 		if tmpl == nil {
 			tmpl = t.new(name)
+		} else if tmpl.escapeErr != nil {
+			return nil, fmt.Errorf("html/template: cannot redefine %q after it has executed", name)
 		}
 		// Restore our record of this text/template to its unescaped original state.
 		tmpl.escapeErr = nil
@@ -228,6 +237,7 @@ func (t *Template) Clone() (*Template, error) {
 			set: make(map[string]*Template),
 		},
 	}
+	ret.set[ret.Name()] = ret
 	for _, x := range textClone.Templates() {
 		name := x.Name()
 		src := t.set[name]
@@ -413,3 +423,10 @@ func parseGlob(t *Template, pattern string) (*Template, error) {
 	}
 	return parseFiles(t, filenames...)
 }
+
+// IsTrue reports whether the value is 'true', in the sense of not the zero of its type,
+// and whether the value has a meaningful truth value. This is the definition of
+// truth used by if and other such actions.
+func IsTrue(val interface{}) (truth, ok bool) {
+	return template.IsTrue(val)
+}