[joepetjr]

Summary

• ST-1. TrackIndex.position_at interpolated longitude as a plain number. A leg from 179 to -179 came out at 0, on the other side of the planet. Longitude now follows the shorter arc and is wrapped into [-180, 180]. Ordinary legs and endpoints are unchanged.
• ST-2. Adds an opt-in strict gap policy. With strict=True, max_gap_min bounds the span between the two bracketing points, so a capture inside a long hole in the track is refused however close it sits to one end. Captures before the first or after the last point are refused.
• Adds fix_at(), which returns TrackFix(lat, lon, inferred). inferred is False only when the time equals a logged point.
• README documents both policies.

Plan units: ST-1, ST-2 (portfolio remediation 2026-09-29).

Compatibility

The default is unchanged. strict=False keeps the old nearest-endpoint rule, position_at still returns a tuple, and the default window is still 90 minutes.

Design decisions to review

• Strict mode is opt-in, so no consumer changes behavior by upgrading.
• The inferred flag lives on the new fix_at, not on position_at, to avoid breaking v0.1.0 callers.
• The midpoint of 179 to -179 is returned as +180.0. The closed range is kept so a logged 180.0 is never rewritten.
• No --strict flag on the command line tool. Consumers pick the mode in code.

Test plan

• ST-1: midpoint both directions, quarter points, endpoint identity, a 100 degree step that does not cross the line. Three were red before the change, with midpoint 0.0 instead of 180.0.
• ST-2: a three hour gap queried near both ends and mid-gap under both policies, end-of-track refusal, exact-point acceptance, the inferred flag.
• Full suite locally: 97 passed. ruff check . and ruff format --check . clean.

Acceptance

• Both date-line midpoint cases stay near the line, and ordinary tracks and endpoints stay correct: parametrized midpoint test, endpoint test, non-crossing test.
• A three hour gap queried near an endpoint is refused under strict and documented under legacy: test_strict_mode_refuses_a_capture_inside_a_gap_wider_than_the_limit, test_legacy_mode_places_a_capture_near_an_endpoint_of_a_three_hour_gap, README policy section.