encoding/asn1: don't convert UTCTime to UTC.

Previously we converted a time to UTC *and* serialized the timezone of
the original time. With this change, we serialize a UTCTime in the
original timezone.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6817048

src/pkg/encoding/asn1/marshal.go

@@ -296,8 +296,7 @@ func marshalTwoDigits(out *forkableWriter, v int) (err error) {
 }
 
 func marshalUTCTime(out *forkableWriter, t time.Time) (err error) {
-	utc := t.UTC()
-	year, month, day := utc.Date()
+	year, month, day := t.Date()
 
 	switch {
 	case 1950 <= year && year < 2000:
@@ -321,7 +320,7 @@ func marshalUTCTime(out *forkableWriter, t time.Time) (err error) {
 		return
 	}
 
-	hour, min, sec := utc.Clock()
+	hour, min, sec := t.Clock()
 
 	err = marshalTwoDigits(out, hour)
 	if err != nil {

src/pkg/encoding/asn1/marshal_test.go

@@ -82,7 +82,7 @@ var marshalTests = []marshalTest{
 	{explicitTagTest{64}, "3005a503020140"},
 	{time.Unix(0, 0).UTC(), "170d3730303130313030303030305a"},
 	{time.Unix(1258325776, 0).UTC(), "170d3039313131353232353631365a"},
-	{time.Unix(1258325776, 0).In(PST), "17113039313131353232353631362d30383030"},
+	{time.Unix(1258325776, 0).In(PST), "17113039313131353134353631362d30383030"},
 	{BitString{[]byte{0x80}, 1}, "03020780"},
 	{BitString{[]byte{0x81, 0xf0}, 12}, "03030481f0"},
 	{ObjectIdentifier([]int{1, 2, 3, 4}), "06032a0304"},