test(cdx): regression guards for migration-critical index ordering

[Admnwk]

Summary

Migration reports from the community describe expression / composite CDX
tags and order-by-number selection coming out "disordered". I could not
reproduce a fault on the current tree — engine-level behaviour for these cases
is correct — so this PR lands the scenarios as regression guards rather
than failing repros, exercised at scale through the public ACE ABI.

Tests added (test-only, no production changes)

• abi_cdx_ordinal_creation_order_test — OrdSetFocus(N) / SET ORDER TO <n> must follow tag creation order, not the alphabetical order of the
  name-keyed "tag of tags" tree. Creating TZ then TA, ordinal 1 must
  resolve to TZ.
• abi_cdx_expr_reindex_order_repro_test — a UPPER(NOME) tag and a
  UPPER(NOME)+CODIGO composite tag over 3000 rows must order ascending after
  both the bulk CREATE INDEX path and the per-record AdsReindex path.
• cdx_bulk_recno_repro_test — build_bulk must keep every key bound to
  its own recno across multiple leaves, including prefix-sharing text keys that
  exercise the dup/trailing-prefix leaf compression.

Result

All pass on the current tree (and on the v1.4.0 tag). /WX clean, MSVC x64.
They lock in the behaviours the reports touch so a future regression in the
bulk builder / expression-key build / ordinal sequence is caught immediately.

🤖 Generated with Claude Code (Opus 4.8)

[gemini-code-assist]

Code Review

This pull request adds three new unit test files to verify CDX index ordering, ordinal creation order, and bulk-load record number binding. The review feedback highlights several potential buffer overflow vulnerabilities when copying directory paths or field names into fixed-size buffers without bounds checks, as well as unsafe casting of string literals to non-const pointers.

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[gemini-code-assist]

If name is longer than 15 characters, std::strlen(name) + 1 will exceed the size of fld, causing a buffer overflow. Adding a REQUIRE check will prevent potential overflows.

Suggested change

	UNSIGNED8 fld[16]; std::memcpy(fld, name, std::strlen(name) + 1);
	REQUIRE(std::strlen(name) < 16);
	UNSIGNED8 fld[16]; std::memcpy(fld, name, std::strlen(name) + 1);

[gemini-code-assist]

If the temporary directory path dir.string() exceeds 255 characters, std::memcpy will overflow the srv buffer. It is safer to add a guard REQUIRE(dir.string().size() < sizeof(srv)); before copying.

Suggested change

	UNSIGNED8 srv[256];
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);
	UNSIGNED8 srv[256];
	REQUIRE(dir.string().size() < sizeof(srv));
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);

[gemini-code-assist]

If the temporary directory path dir.string() exceeds 255 characters, std::memcpy will overflow the srv buffer. It is safer to add a guard REQUIRE(dir.string().size() < sizeof(srv)); before copying.

Suggested change

	UNSIGNED8 srv[256];
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);
	UNSIGNED8 srv[256];
	REQUIRE(dir.string().size() < sizeof(srv));
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);

[gemini-code-assist]

If the temporary directory path dir.string() exceeds 255 characters, std::memcpy will overflow the srv buffer. It is safer to add a guard REQUIRE(dir.string().size() < sizeof(srv)); before copying.

Suggested change

	UNSIGNED8 srv[256];
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);
	UNSIGNED8 srv[256];
	REQUIRE(dir.string().size() < sizeof(srv));
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);

[gemini-code-assist]

If the temporary directory path dir.string() exceeds 255 characters, std::memcpy will overflow the srv buffer. It is safer to add a guard REQUIRE(dir.string().size() < sizeof(srv)); before copying.

Suggested change

	UNSIGNED8 srv[256];
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);
	UNSIGNED8 srv[256];
	REQUIRE(dir.string().size() < sizeof(srv));
	std::memcpy(srv, dir.string().c_str(), dir.string().size() + 1);

[gemini-code-assist]

Casting string literals directly to non-const pointers (UNSIGNED8*) is risky and can lead to undefined behavior if the underlying API ever attempts to modify the buffer. It is safer to use local mutable arrays on the stack.

Suggested change

	REQUIRE(AdsCreateIndex61(hTable, fn, (UNSIGNED8*)"TZ", (UNSIGNED8*)"UPPER(NOME)",
	nullptr, nullptr, 0, 512, &hZ) == 0);
	REQUIRE(AdsCreateIndex61(hTable, fn, (UNSIGNED8*)"TA", (UNSIGNED8*)"CODE",
	nullptr, nullptr, 0, 512, &hA) == 0);
	UNSIGNED8 tagZ[16] = "TZ";
	UNSIGNED8 exprZ[32] = "UPPER(NOME)";
	UNSIGNED8 tagA[16] = "TA";
	UNSIGNED8 exprA[32] = "CODE";
	REQUIRE(AdsCreateIndex61(hTable, fn, tagZ, exprZ,
	nullptr, nullptr, 0, 512, &hZ) == 0);
	REQUIRE(AdsCreateIndex61(hTable, fn, tagA, exprA,
	nullptr, nullptr, 0, 512, &hA) == 0);

[Admnwk]

Withdrawing to re-verify against real-world data before resubmitting.