# Review by Linus Torvalds (Round 3)

---

VERDICT: approve

FINDINGS:
- [src/colonyos/orchestrator.py:1720-1738]: Branch checkout + try/finally restore pattern is correct and defensive. The finally block at line 1869 handles cleanup even on unhandled exceptions.
- [src/colonyos/cli.py:2069-2072]: Snapshot-under-lock pattern for `should_process_thread_fix` avoids holding `state_lock` during potentially slow detection. Clean.
- [src/colonyos/cli.py:2017-2018]: `parent_item.fix_rounds += 1` inside `state_lock` prevents TOCTOU races on the round counter. Correct ordering.
- [src/colonyos/cli.py:2664-2682]: Head SHA propagation after successful fix round (`parent_item.head_sha = new_head_sha`) solves multi-round staleness correctly.
- [src/colonyos/orchestrator.py:1694-1699]: Defense-in-depth: `is_valid_git_ref()` called at both enqueue time (cli.py:2632) and execution time (orchestrator.py:1694). Necessary because queue state is deserialized from JSON.
- [src/colonyos/sanitize.py:47-63]: Slack link sanitizer is minimal and correct. Two-pass approach handles common cases without over-engineering.
- [src/colonyos/slack.py:135-189]: `should_process_thread_fix` is a pure function — no side effects, no I/O. Testable and correct.
- [src/colonyos/slack.py:90-132]: `should_process_message()` remains completely unchanged, satisfying FR-2.
- [src/colonyos/instructions/thread_fix.md]: Template interpolation is safe because `is_valid_git_ref()` constrains the character set upstream.

SYNTHESIS:
The implementation is solid, correct, and appropriately simple. The data structures tell the story: `QueueItem` gets four new fields (`branch_name`, `fix_rounds`, `parent_item_id`, `head_sha`) that carry the entire thread-fix state model. Code paths are cleanly separated — `should_process_message()` is untouched (FR-2), `should_process_thread_fix()` handles detection, and `QueueExecutor` dispatches on `source_type`. The security model is sound: sanitization runs on all thread reply text via the existing `sanitize_slack_content()` → `strip_slack_links()` + `sanitize_untrusted_content()` chain; git refs are validated at both enqueue and execution boundaries; HEAD SHA verification catches force-push tampering. All 456 tests pass, covering happy paths, edge cases (deleted branch, merged PR, max rounds, non-allowlisted user), and backwards compatibility. The `run_thread_fix()` orchestrator correctly skips Plan/triage (FR-8, FR-9) and runs Implement → Verify → Deliver. No TODOs, no placeholder code, no unnecessary abstractions. Ship it.