diff --git a/src/pkg/html/template/clone_test.go b/src/pkg/html/template/clone_test.go
index c612775d4f..5907ff2c3e 100644
--- a/src/pkg/html/template/clone_test.go
+++ b/src/pkg/html/template/clone_test.go
@@ -113,3 +113,10 @@ func TestClone(t *testing.T) {
t.Errorf("t3: got %q want %q", got, want)
}
}
+
+// This used to crash; http://golang.org/issue/3281
+func TestCloneCrash(t *testing.T) {
+ t1 := New("all")
+ Must(t1.New("t1").Parse(`{{define "foo"}}foo{{end}}`))
+ t1.Clone()
+}
diff --git a/src/pkg/html/template/template.go b/src/pkg/html/template/template.go
index b0bae7a54f..95a3027c46 100644
--- a/src/pkg/html/template/template.go
+++ b/src/pkg/html/template/template.go
@@ -160,9 +160,11 @@ func (t *Template) Clone() (*Template, error) {
if src == nil || src.escaped {
return nil, fmt.Errorf("html/template: cannot Clone %q after it has executed", t.Name())
}
- x.Tree = &parse.Tree{
- Name: x.Tree.Name,
- Root: x.Tree.Root.CopyList(),
+ if x.Tree != nil {
+ x.Tree = &parse.Tree{
+ Name: x.Tree.Name,
+ Root: x.Tree.Root.CopyList(),
+ }
}
ret.set[name] = &Template{
false,