text/template: initialize template before locking it

For #39807 Fixes #48436 Change-Id: I75f82fd8738dd2f11f0c69b1230e1be1abc36024 Reviewed-on: https://go-review.googlesource.com/c/go/+/350730 Trust: Ian Lance Taylor <[email protected]> Trust: Daniel Martí <[email protected]> Run-TryBot: Ian Lance Taylor <[email protected]> TryBot-Result: Go Bot <[email protected]> Reviewed-by: Daniel Martí <[email protected]>
cloudflare · Sep 20, 2021 · ba1c52d · ba1c52d
1 parent 6e81f78
commit ba1c52d
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/src/text/template/multi_test.go b/src/text/template/multi_test.go
@@ -452,3 +452,13 @@ func TestIssue19294(t *testing.T) {
  }
  }
 }
+
+// Issue 48436
+func TestAddToZeroTemplate(t *testing.T) {
+ tree, err := parse.Parse("c", cloneText3, "", "", nil, builtins())
+ if err != nil {
+ t.Fatal(err)
+ }
+ var tmpl Template
+ tmpl.AddParseTree("x", tree["c"])
+}
diff --git a/src/text/template/template.go b/src/text/template/template.go
@@ -127,9 +127,9 @@ func (t *Template) copy(c *common) *Template {
 // its definition. If it has been defined and already has that name, the existing
 // definition is replaced; otherwise a new template is created, defined, and returned.
 func (t *Template) AddParseTree(name string, tree *parse.Tree) (*Template, error) {
+ t.init()
  t.muTmpl.Lock()
  defer t.muTmpl.Unlock()
- t.init()
  nt := t
  if name != t.name {
  nt = t.New(name)