fix: executor shutdown race, dropped kwargs, chunk revalidation, unknown-class cache

[ariostas]

🤖 AI text below 🤖

Four independent, low-risk correctness fixes from #1688 (findings 1–3 of "PR 3" and finding 3 of "PR 5"). Grouped because each is a few lines with no API surface; happy to split if you'd rather review them separately.

Note this deliberately does not include finding 4 of "PR 3" (with uproot.open(...) not shutting down attached executors). That one changes what __exit__ closes and would shut down a user-supplied executor reused across files, so it needs its own discussion.

1. Submit racing with shutdown was orphaned

ThreadPoolExecutor.shutdown queues one sentinel per worker and then joins them; ResourceThreadPoolExecutor only set _closed after that returned. A submit in that window passed the guard, landed behind a sentinel, and was never run — its Future blocked forever. Reproduced by occupying the single worker so join() blocks:

ex.closed during shutdown: False
late submit ACCEPTED
late future ORPHANED (timed out, would hang forever)

Sets the flag before queuing the sentinels. ThreadPoolExecutor now gets the same guarantee, which it previously lacked entirely.

2. submit accepted keyword arguments and discarded them

ThreadPoolExecutor.submit(task, /, *args, **kwargs) built Future(task, args), so submit(task, 1, x=3) silently ran task(1). Now carried on the Future.

3. A failed chunk length check only failed once

Chunk.wait assigned self._raw_data before validating its length, so a chunk declared as 5 bytes but backed by 3 raised OSError on first access and returned the truncated buffer on every access after that. The data is now published only once it has passed.

4. Unknown model classes were cached by classname alone

uproot.unknown_classes was keyed on the bare classname, so version 2 of a class got back the class built for version 1 (Unknown_MyClass_v1), and a versionless UnknownClass and a versioned UnknownClassVersion for the same classname evicted each other. Keyed on the encoded classname instead, which already carries both distinctions. The dict stays str -> class.

Tests

tests/test_1688_source_hygiene.py, 9 tests; 6 fail on main.

Full suite passes locally (1032 passed, 90 skipped).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.94%. Comparing base (e598b61) to head (5c9785e).

Additional details and impacted files

Files with missing lines	Coverage Δ
src/uproot/model.py	81.69% <100.00%> (+1.16%)	⬆️
src/uproot/reading.py	80.95% <100.00%> (+0.04%)	⬆️
src/uproot/source/chunk.py	84.00% <100.00%> (+1.24%)	⬆️
src/uproot/source/futures.py	89.52% <100.00%> (+0.45%)	⬆️

... and 1 file with indirect coverage changes