The max_delete case allowlisted the tree aspect because the surviving extras after a partial --max-delete abort are deletion-order dependent. Under FASTSYNC_PARITY_STRICT a run where the orders coincide was reported as a stale entry (CI failure), while removing the entry made the order-dependent tree mismatch fail. Add a per-case 'compare_tree' flag: max_delete now asserts rc=25 plus the survivor count via extra_check instead of exact tree identity, so the allowlist can be empty. Burn-down reached zero.
- --delete-delay: state that the reported count advances on actual removal
while --max-delete is charged at plan/snapshot time (defer_add/planned).
A new differential shows rsync instead charges on actual removals and
recursively removes a queued directory, so the row moves to Caveat
(matrix 111/13/33) and the residual is pinned by tests.
- Add a deterministic unit test (plan-time budget charge), a FastSync
integration test (byte-barrier refill + --max-delete), and an rsync
differential for a refilled deferred directory.
- Soften the --fuzzy summary: the tree is byte-exact by design, so it is
pinned by the threshold suite, not a byte-level differential.
- README: describe what -m parity actually selects; fix the allowlist
example to the real max_delete entry.
- xdist-safe delete-timing fixture names (timing and --threads mode).
- Renumber the duplicate HANDOFF item 9 to 10; add the missing final
newline to test_checksum.c.
- Expose ignore_errors_allows_delete and unit-test the deletion gate
without a privileged source directory; update the stale deleted-count
doc comment.
No production behavior changes.
Add tests/integration/test_differential_parity.py plus a shared
parity_harness.py and a data-driven parity_caveats.py allowlist. The gate
runs real rsync 3.4.1 and FastSync over the same corpora, compares the
destination trees (paths, hashes, symlink targets, modes, hard-link
grouping) and the normalized -i/--stats/--out-format output, and fails on
any difference not listed in the allowlist. Stale allowlist entries warn
(or fail under FASTSYNC_PARITY_STRICT=1) so the residual list shrinks.
Register parity/parity_ci markers and wire a fast PR job (parity_ci) plus a
push-only full job (parity, strict) into .gitea/workflows/ci.yaml.
Document the gate and the allowlist workflow in tests/integration/README.md.