Formal models and scripts: fuzzy-levenshtein

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

• LuceneLevenshteinDistance.getDistance returns 0 for two empty strings and max(n, m) (for example 3.0) when one string is empty, instead of a similarity score (a 2011 regression from LUCENE-3662) (finding LFV-350; repro)

Files

• model/fuzzy_prune_smt.py (used for LFV-350)

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.