proto: fix interactions with v2 extensions

Update to the latest version of google.golang.org/protobuf.

https://golang.org/cl/192458 changed the Go
representation of repeated extension fields to []T (from *[]T). Make the
corresponding update here.

Change-Id: Ia67e3899069d83f145569f01635f4ae3d9e664b8
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/204798
Reviewed-by: Joe Tsai <[email protected]>

Author: neild

go.mod

@@ -2,4 +2,4 @@ module github.com/golang/protobuf
 
 go 1.9
 
-require google.golang.org/protobuf v0.0.0-20190828183429-79bfdbe45be2
+require google.golang.org/protobuf v0.0.0-20191031162342-c826885a2abe

go.sum

@@ -9,6 +9,7 @@ github.com/golang/protobuf v1.2.1-0.20190620192300-1ee46dfd80dd/go.mod h1:+CMAsi
 github.com/golang/protobuf v1.2.1-0.20190806214225-7037721e6de0/go.mod h1:tDQPRlaHYu9yt1wPgdx85inRiLvUCuJZXsYjC0mwc1c=
 github.com/golang/protobuf v1.2.1-0.20190820204156-2da1b93405dd/go.mod h1:x87I3ou7ehf/yR6iQ88MkyDogdxXN04TELJ7HVy7V7I=
 github.com/golang/protobuf v1.2.1-0.20190820213554-ae1d65bc5435/go.mod h1:k7dGkiTZ3rjVDhKSpGt+x1zDzAePJk4jdhoBwIkQgBo=
+github.com/golang/protobuf v1.2.1-0.20191004062209-62f67f1ea9df/go.mod h1:o4el5ABfDjqFlwwvAq2OIgAPeNXQYUkhtrjNPXy6T6I=
 github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 google.golang.org/protobuf v0.0.0-20190514172829-e89e6244e0e8/go.mod h1:791zQGC15vDqjpmPRn1uGPu5oHy/Jzw/Q1n5JsgIIcY=
@@ -27,3 +28,5 @@ google.golang.org/protobuf v0.0.0-20190820213257-f1e905b04207 h1:ulV4hvtdAg7Xsym
 google.golang.org/protobuf v0.0.0-20190820213257-f1e905b04207/go.mod h1:UJqt2ZERO8/qk5A9t8Ujq6OJ+MNvOQpg9X4RKyYz9Ho=
 google.golang.org/protobuf v0.0.0-20190828183429-79bfdbe45be2 h1:g52BKWg08C9Z3iSV/mBCfoP+ObYXKCgdXF+p1EB9zD0=
 google.golang.org/protobuf v0.0.0-20190828183429-79bfdbe45be2/go.mod h1:fYMzYhnMXLj/kGDPzNOptS3IFFlQjWTlu2j3ZPET2lw=
+google.golang.org/protobuf v0.0.0-20191031162342-c826885a2abe h1:TqSqUz1beyIiDb4QdI6lZDstr9RxMfftdKQ0eonA0Dc=
+google.golang.org/protobuf v0.0.0-20191031162342-c826885a2abe/go.mod h1:qKrTvhhUFcTIUF6KuejTfRdHXKeBPoa4mtynR6usTss=

proto/extensions.go

@@ -486,16 +486,6 @@ func extensionAsLegacyType(v interface{}) interface{} {
 		rv2 := reflect.New(rv.Type())
 		rv2.Elem().Set(rv)
 		v = rv2.Interface()
-	case reflect.Ptr:
-		// Represent slice types as the value itself.
-		switch rv.Type().Elem().Kind() {
-		case reflect.Slice:
-			if rv.IsNil() {
-				v = reflect.Zero(rv.Type().Elem()).Interface()
-			} else {
-				v = rv.Elem().Interface()
-			}
-		}
 	}
 	return v
 }
@@ -505,7 +495,7 @@ func extensionAsLegacyType(v interface{}) interface{} {
 func extensionAsStorageType(v interface{}) interface{} {
 	switch rv := reflect.ValueOf(v); rv.Kind() {
 	case reflect.Ptr:
-		// Represent slice types as the value itself.
+		// Represent non-slice types as the value itself.
 		switch rv.Type().Elem().Kind() {
 		case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String:
 			if rv.IsNil() {
@@ -514,13 +504,6 @@ func extensionAsStorageType(v interface{}) interface{} {
 				v = rv.Elem().Interface()
 			}
 		}
-	case reflect.Slice:
-		// Represent slice types as a pointer to the value.
-		if rv.Type().Elem().Kind() != reflect.Uint8 {
-			rv2 := reflect.New(rv.Type())
-			rv2.Elem().Set(rv)
-			v = rv2.Interface()
-		}
 	}
 	return v
 }