encoding/xml: fix decoding of xml.Name with sub-elements

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5569090

src/pkg/encoding/xml/marshal_test.go

@@ -532,6 +532,11 @@ var marshalTests = []struct {
 		Value:     &NameInField{Name{Space: "ns", Local: "foo"}},
 		ExpectXML: `<NameInField><foo xmlns="ns"></foo></NameInField>`,
 	},
+	{
+		Value:         &NameInField{Name{Space: "ns", Local: "foo"}},
+		ExpectXML:     `<NameInField><foo xmlns="ns"><ignore></ignore></foo></NameInField>`,
+		UnmarshalOnly: true,
+	},
 
 	// Marshaling zero xml.Name uses the tag or field name.
 	{

src/pkg/encoding/xml/read.go

@@ -265,12 +265,13 @@ func (p *Decoder) unmarshal(val reflect.Value, start *StartElement) error {
 		saveData = v
 
 	case reflect.Struct:
-		sv = v
-		typ := sv.Type()
+		typ := v.Type()
 		if typ == nameType {
 			v.Set(reflect.ValueOf(start.Name))
 			break
 		}
+
+		sv = v
 		tinfo, err = getTypeInfo(typ)
 		if err != nil {
 			return err