~bigbes/tarantool-protobuf: 11b9ebde

c_runtime: strict-decode parity with pure-Lua codec (rc8)

The C decoder accepted wire types 6/7, field number 0, field numbers
beyond 29 bits, overlong tag varints, invalid UTF-8 in string fields,
and unmatched proto2 SGROUPs — each of which the pure-Lua decoder
already rejected. It also replaced (instead of merged) when a singular
message field appeared more than once on the wire, dropping
sub-message scalars from the prior occurrence.

decode_body: reject wt 6/7 / field 0 / fn > 2^29-1 / overlong tag
varint up front; track egroup_seen so a group body that runs off the
end of the buffer fails loudly. dec_push_kind STRING: port wire.lua's
RFC 3629 validator (utf8.len equivalent) — covers singular, repeated,
oneof, map-key, and map-value via the same code path. Singular message
dispatch in decode_body and decode_extension_into: look up an existing
prev table at result[name] and merge via the new
merge_subresult_into, which ports codec.lua's merge_message (recursive
sub-message, repeated concat, map last-wins per key, skip for WKT
custom-decode).

Regression coverage in test/conformance_test.lua's conformance.core
group: pre-existing tests already pinned the wire-type, tag, UTF-8
(singular/repeated/oneof), and merge cases — those now also exercise
the C path under PB_ENABLE_C=1. Two gaps remained — map-key/value
UTF-8 and proto2 group balancing — both covered now via four new
tests, with proto2 routed through a TestAllTypesProto2 helper.

PB_ENABLE_C=1 just test: 1043/1043 (baseline 1039 + 4 new).
PB_ENABLE_C=1 just conformance-c: 0 unexpected failures (was 77).
just conformance (pure-Lua path): unchanged — no regression.

Closes rc8

Eugene Blikh <bigbes@gmail.com> — 2026-05-23 19:52:05 UTC

Commit 11b9ebde83fd05574699fd26b0fd3c82117ab6bbview raw patch

Parent(s): 1eb062c1

2 changed file(s)

FileStatus+
runtime/pb/c/c_runtime.c M +276 -5
test/conformance_test.lua M +65