tree 1c0f6173156ebc1a82be79d309098ec59e2405ad
parent a522d5fa0c2268a489b0c8118de34e92830bd602
author Damien Neil <dneil@google.com> 1580252024 -0800
committer Damien Neil <dneil@google.com> 1580333731 +0000

internal/impl: lazy extension decoding

Historically, extensions have been placed in the unknown fields section
of the unmarshaled message and decoded lazily on demand. The current
unmarshal implementation decodes extensions eagerly at unmarshal time,
permitting errors to be immediately reported and correctly detecting
unset required fields in extension values.

Add support for validated lazy extension decoding, where the extension
value is fully validated at initial unmarshal time but the fully
unmarshaled message is only created lazily.

Make this behavior conditional on the protolegacy flag for now.

Change-Id: I9d742496a4bd4dafea83fca8619cd6e8d7e65bc3
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/216764
Reviewed-by: Joe Tsai <joetsai@google.com>