Chunk oversized JSON string writes in JsonToBinaryStream

[Amemoyoi]

This change avoids oversized raw writes in the proto3 JSON-to-binary streaming path.

Changes:

• chunk oversized writes in ParseProto3Type::SetString() instead of passing a size_t length directly into WriteRaw(const void*, int)
• add a focused regression test for the chunking behavior at the INT_MAX + 1 boundary

[esrauchg]

Thank you for raising this!

Serializing strings above 2 GiB is not supported by protobuf in general (our length-prefix format has an int32 for sizes, so strings that large aren't representable in our main format at all).

I think we likely would prefer to serialize-fail if such a condition is hit rather than trying to gracefully chunk up the writes: do you think you could update the PR to do?

[Amemoyoi]

Thanks, that makes sense.
I’ve updated the PR to fail cleanly when a JSON string/bytes value exceeds the supported INT32_MAX serialization limit, instead of chunking the writes.

[esrauchg]

Thank you!

[esrauchg]

Thanks!

[Amemoyoi]

Thanks again for the review.
I’ve synced the branch with main, and the blocking checks appear to be passing now.
Please let me know if there’s anything else needed from my side before merge.

[esrauchg]

Unfortunately looks like theres a build breakage with latest proposed change, are you able to fix?

Thanks!

[Amemoyoi]

Thanks for the heads up. The breakage was from defining the helper in the header with external linkage. I’ve updated it to be inline and pushed the fix.