internal/impl: fix for lazy decoding of groups

Bit of a weird case in why this wasn't caught by tests: When validating
extension groups, we were validating an empty buffer rather than the
message content. For groups, this validation always fails due to a lack
of a group end tag. We'd then skip lazy decoding of the extension field
and proceed with eager decoding, which would behave correctly.

Change extension validation to report an error immediately on an invalid
result from the validator, which is both safe (assuming we trust the
validator) and would have caught this problem (by failing to decode the
extension field, rather than silently failing to eager decoding).

Change-Id: Id6c2d21fb687062bc74d9eb93760a1c24a6fe883
Reviewed-by: Joe Tsai <>
1 file changed
tree: 83280820d17bced8c729b138d8b95c2654b132d6
  1. .gitignore
  2. .travis.yml
  9. cmd/
  10. compiler/
  11. encoding/
  12. go.mod
  13. go.sum
  14. integration_test.go
  15. internal/
  16. proto/
  17. reflect/
  18. regenerate.bash
  19. release.bash
  20. runtime/
  21. test.bash
  22. testing/
  23. types/

Next Generation Go Protocol Buffers

WARNING: This repository is in active development. There are no guarantees about API stability. Breaking changes will occur until a stable release is made and announced.

This repository is for the development of the next major Go implementation of protocol buffers. This library makes breaking API changes relative to the existing Go protobuf library. Of particular note, this API aims to make protobuf reflection a first-class feature of the API and implements the protobuf ecosystem in terms of reflection.

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