jsonpb: merge https://github.com/golang/protobuf/pull/255

treat `null` JSON values for `Timestamp` and `Duration` as defaults

* Handle unmarshalling of null json values for timestamp and duration types
* Add tests for json values that include nulls for timestamp and duration
PiperOrigin-RevId: 139390817

jsonpb/jsonpb.go

diff --git a/jsonpb/jsonpb.go b/jsonpb/jsonpb.go
index 1fc8ae8..82c6162 100644
--- a/jsonpb/jsonpb.go
+++ b/jsonpb/jsonpb.go
@@ -585,7 +585,14 @@
 		case "Any":
 			return fmt.Errorf("unmarshaling Any not supported yet")
 		case "Duration":
-			unq, err := strconv.Unquote(string(inputValue))
+			ivStr := string(inputValue)
+			if ivStr == "null" {
+				target.Field(0).SetInt(0)
+				target.Field(1).SetInt(0)
+				return nil
+			}
+
+			unq, err := strconv.Unquote(ivStr)
 			if err != nil {
 				return err
 			}
@@ -600,7 +607,14 @@
 			target.Field(1).SetInt(ns)
 			return nil
 		case "Timestamp":
-			unq, err := strconv.Unquote(string(inputValue))
+			ivStr := string(inputValue)
+			if ivStr == "null" {
+				target.Field(0).SetInt(0)
+				target.Field(1).SetInt(0)
+				return nil
+			}
+
+			unq, err := strconv.Unquote(ivStr)
 			if err != nil {
 				return err
 			}

jsonpb/jsonpb_test.go

diff --git a/jsonpb/jsonpb_test.go b/jsonpb/jsonpb_test.go
index 78f67c4..e237df5 100644
--- a/jsonpb/jsonpb_test.go
+++ b/jsonpb/jsonpb_test.go
@@ -467,9 +467,11 @@
 	{"camelName input", Unmarshaler{}, `{"oBool":true}`, &pb.Simple{OBool: proto.Bool(true)}},
 
 	{"Duration", Unmarshaler{}, `{"dur":"3.000s"}`, &pb.KnownTypes{Dur: &durpb.Duration{Seconds: 3}}},
+	{"null Duration", Unmarshaler{}, `{"dur":null}`, &pb.KnownTypes{Dur: &durpb.Duration{Seconds: 0}}},
 	{"Timestamp", Unmarshaler{}, `{"ts":"2014-05-13T16:53:20.021Z"}`, &pb.KnownTypes{Ts: &tspb.Timestamp{Seconds: 14e8, Nanos: 21e6}}},
 	{"PreEpochTimestamp", Unmarshaler{}, `{"ts":"1969-12-31T23:59:58.999999995Z"}`, &pb.KnownTypes{Ts: &tspb.Timestamp{Seconds: -2, Nanos: 999999995}}},
 	{"ZeroTimeTimestamp", Unmarshaler{}, `{"ts":"0001-01-01T00:00:00Z"}`, &pb.KnownTypes{Ts: &tspb.Timestamp{Seconds: -62135596800, Nanos: 0}}},
+	{"null Timestamp", Unmarshaler{}, `{"ts":null}`, &pb.KnownTypes{Ts: &tspb.Timestamp{Seconds: 0, Nanos: 0}}},
 
 	{"DoubleValue", Unmarshaler{}, `{"dbl":1.2}`, &pb.KnownTypes{Dbl: &wpb.DoubleValue{Value: 1.2}}},
 	{"FloatValue", Unmarshaler{}, `{"flt":1.2}`, &pb.KnownTypes{Flt: &wpb.FloatValue{Value: 1.2}}},