Revert "html/template: prevent aliasing of parse Trees via AddParseTree"

This reverts commit cd0a5f08293e1bf1fac41ae6438d495318cd52fb, which
unnecessarily restricts the use of AddParseTree.

Change-Id: I1155214a20ba08981d604404e79fff54874fd8e4
Reviewed-on: https://go-review.googlesource.com/83919
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/src/html/template/escape_test.go b/src/html/template/escape_test.go
index 949985fe4a7dec1bfecf0bed457f6a5844a15edb..96684793bdc629b1b8679b4605bbc746e7311979 100644 (file)
--- a/src/html/template/escape_test.go
+++ b/src/html/template/escape_test.go
@@ -1846,7 +1846,7 @@ func TestErrorOnUndefined(t *testing.T) {
 
        err := tmpl.Execute(nil, nil)
        if err == nil {
-               t.Fatal("expected error")
+               t.Error("expected error")
        }
        if !strings.Contains(err.Error(), "incomplete") {
                t.Errorf("expected error about incomplete template; got %s", err)
@@ -1866,10 +1866,10 @@ func TestIdempotentExecute(t *testing.T) {
        for i := 0; i < 2; i++ {
                err = tmpl.ExecuteTemplate(got, "hello", nil)
                if err != nil {
-                       t.Fatalf("unexpected error: %s", err)
+                       t.Errorf("unexpected error: %s", err)
                }
                if got.String() != want {
-                       t.Fatalf("after executing template \"hello\", got:\n\t%q\nwant:\n\t%q\n", got.String(), want)
+                       t.Errorf("after executing template \"hello\", got:\n\t%q\nwant:\n\t%q\n", got.String(), want)
                }
                got.Reset()
        }
@@ -1877,7 +1877,7 @@ 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.Fatalf("unexpected error: %s", err)
+               t.Errorf("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;".
@@ -1887,19 +1887,6 @@ 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/src/html/template/template.go b/src/html/template/template.go
index 9dc066855f1b4d924f44b417df988dcaa2b0558b..4641a37da3cddbc12d83b08cca835f4469082ced 100644 (file)
--- a/src/html/template/template.go
+++ b/src/html/template/template.go
@@ -219,11 +219,6 @@ 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