tree 9562cc478d673b9a9cd038a17d1aaa780a208fee
parent f2c4ddc7a11e20ffe8f2fd80d560a9a246cde17b
author Damien Neil <dneil@google.com> 1569455475 -0700
committer Damien Neil <dneil@google.com> 1569531279 +0000

internal/impl: call Marshal/Unmarshal methods on legacy types

Call the Marshal or Unmarshal method on legacy messages implementing
protoV1.Marshaler or protoV2.Unmarshaler.

We do this in the impl package by creating an appropriate function in
the protoiface.Methods struct for legacy messages.

In proto.MarshalAppend, return the bytes provided by the fast-path
marshal function even when the returned error is non-nil.

Fixes golang/protobuf#955

Change-Id: I36924af9ff959a946c43f2295ef3202216e81b32
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/197357
Reviewed-by: Joe Tsai <joetsai@google.com>