tree 83eb3482279281b6a76819e0c2907fed59ac4e31
parent 302cb325fb1fd440612b28748323a20ee2d38d16
author Joe Tsai <joetsai@digital-static.net> 1563003881 -0700
committer Joe Tsai <joetsai@digital-static.net> 1563220385 +0000

all: support enforce_utf8 override

In 2014, when proto3 was being developed, there were a number of early
adopters of the new syntax. Before the finalization of proto3 when
it was released in open-source in July 2016, a decision was made to
strictly validate strings in proto3. However, some of the early adopters
were already using invalid UTF-8 with string fields.
The google.protobuf.FieldOptions.enforce_utf8 option only exists to support
those grandfathered users where they can opt-out of the validation logic.
Practical use of that option in open source is impossible even if a user
specifies the proto1_legacy build tag since it requires a hacked
variant of descriptor.proto that is not externally available.

This CL supports enforce_utf8 by modifiyng internal/filedesc to
expose the flag if it detects it in the raw descriptor.
We add an strs.EnforceUTF8 function as a centralized place to determine
whether to perform validation. Validation opt-out is supported
only in builds with legacy support.

We implement support for validating UTF-8 in all proto3 string fields,
even if they are backed by a Go []byte.

Change-Id: I9c0628b84909bc7181125f09db730c80d490e485
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/186002
Reviewed-by: Damien Neil <dneil@google.com>