Formal models and scripts: query-object-contracts

Tools: Python

These are the working models and scripts this part of the hunt used. Some encode the code as it is (a counterexample is the expected result), others a fixed or correct variant; read the header comment of each file. Paths inside them were replaced by placeholders such as $LUCENE (a Lucene checkout) and $WORK.

Findings

• DisjunctionMaxQuery and LatLonPoint.newDistanceFeatureQuery accept a NaN tie-breaker or pivot distance (the pivot also +Infinity) because their range checks are false for NaN, so hits score NaN and a NaN query is not equal to itself (finding LFV-304; repro · finding page)

Files

• query-range-checks-admit-nan/model/fp_param_contracts.py (used for LFV-304)

How to run

• Python: python3 <file>.py; scripts that import z3 need the z3-solver package.

Snapshot of 2026-11-03. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.