Formal models and scripts: hunspell-synthetic-dictionary-differential

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

• Hunspell spell() skips the per-entry checks on COMPOUNDRULE compound parts, so it accepts compounds that C Hunspell rejects: a KEEPCASE first part in capitalized or upper case, a FORCEUCASE last part in lower case, and a NEEDAFFIX or FORBIDDENWORD entry as a first or middle part (finding LFV-731; repro · finding page)

Files

• harness/compare.py (used for LFV-731)
• harness/gen_cpd.py (used for LFV-731)
• harness/minimize.py (used for LFV-731)

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.