From d3d8852d8997a6429cbd498138908e537869a6ef Mon Sep 17 00:00:00 2001 From: Rob Pike Date: Sun, 24 Oct 2021 15:44:15 +1100 Subject: text/template: use reflect.Value.FieldByIndexErr to avoid a crash on a nil pointer as an embedded field. Fixes #48215 Change-Id: I214faa6e3cf08cdec1c01035e4bbca0900c6a408 Reviewed-on: https://go-review.googlesource.com/c/go/+/357963 Trust: Rob Pike Run-TryBot: Rob Pike TryBot-Result: Go Bot Reviewed-by: Ian Lance Taylor --- src/text/template/exec_test.go | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'src/text/template/exec_test.go') diff --git a/src/text/template/exec_test.go b/src/text/template/exec_test.go index 9c0772945e..3c40aa901e 100644 --- a/src/text/template/exec_test.go +++ b/src/text/template/exec_test.go @@ -1787,3 +1787,26 @@ func TestIssue39807(t *testing.T) { wg.Wait() } + +// Issue 48215: embedded nil pointer causes panic. +// Fixed by adding FieldByIndexErr to the reflect package. +func TestIssue48215(t *testing.T) { + type A struct { + S string + } + type B struct { + *A + } + tmpl, err := New("").Parse(`{{ .S }}`) + if err != nil { + t.Fatal(err) + } + err = tmpl.Execute(io.Discard, B{}) + // We expect an error, not a panic. + if err == nil { + t.Fatal("did not get error for nil embedded struct") + } + if !strings.Contains(err.Error(), "reflect: indirection through nil pointer to embedded struct field A") { + t.Fatal(err) + } +} -- cgit v1.3-5-g9baa