THRIFT-6048: Limit struct read/write recursion depth in Perl library

[Jens-G]

THRIFT-6048: Limit struct read/write recursion depth in the Perl library

Change

The Perl generator wraps each generated read()/write() body with incrementRecursionDepth() / eval / decrementRecursionDepth() on Thrift::Protocol (limit DEFAULT_RECURSION_DEPTH = 64, Thrift::TProtocolException::DEPTH_LIMIT on excess). Previously only skip() was bounded. Unions and exceptions are generated through the same path, so they are bounded too.

Test

Replaces the isolated counter test with a generated-code round-trip (lib/perl/t/recursion_depth.t) over a recursive struct (RecTree), union (RecUnion) and exception (RecError) from a new RecursionDepth.thrift, on a real BinaryProtocol. For each of the three kinds:

• a chain at the limit round-trips (also proving the generator and protocol guards do not double-count);
• a chain past the limit is rejected on write;
• a hand-serialized over-limit payload is rejected on read, crafted with the real recursive field (id 1 = list<self>) so the reader recurses through the guarded path rather than the separate, unbounded skip().

Each rejection asserts the DEPTH_LIMIT code specifically, not merely that an exception was thrown. Validated locally with Perl 5.34 (Test::More + Test::Exception): 21/21 ok. Perl is binary-only (no Compact/JSON modules). No functional Perl CI (--without-perl); SCA runs perlcritic, which excludes t/.

🤖 Generated with Claude Code