Fix/annotated screenshot race - #378
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Jeomon merged 3 commits intoAug 12, 2026
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This PR fixes the annotated-screenshot race condition.
Problem:
Desktop.get_annotated_screenshot()drew annotations onto one shared PILImageDrawobject fromThreadPoolExecutorthreads. PIL'sImageDrawisn't thread-safe, so labels rendered corrupted and output was non-deterministic.Fix: draw annotations sequentially in a for-loop. PIL drawing is GIL-bound, so the thread pool never gave real parallelism — same speed, no race.
Testing: added
tests/test_annotation_thread_safety.py— renders identical input repeatedly and asserts byte-identical output. Passes here; fails on the old threaded code (reproduced 100 distinct outputs). Full suite: 200 passed (6 pre-existing unrelated failures intests/test_tree_views.py). Ruff clean.