Formal models and scripts: docandscorequery-public-factory-count-and-iterator-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

• DocAndScoreQuery.createDocAndScoreQuery (public on main since #16686) keeps repeated doc ids: a document listed twice is counted and returned twice, and a repeated first document of a segment is iterated by the previous segment as doc id == maxDoc (a deleted or MUST_NOT-excluded document comes back, or a search with deletions or a doc-values sort throws) (finding LFV-955; repro · finding page)

Files

• docandscorequery-factory-accepts-repeated-docs/model/findsegstarts_z3.py (used for LFV-955)

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.