Formal models and scripts: store-cross-impl-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

• BufferedIndexInput.refill marks its buffer as filled before readInternal succeeds, so after a failed read the next reads of the same input return up to one buffer of stale bytes instead of re-reading or throwing (regression of LUCENE-1262 since 8.6.0) (finding LFV-492; repro)

Files

• bufferedindexinput-refill-commits-state-before-read/model/bii_refill_model.py (used for LFV-492)

How to run

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

Snapshot of 2026-11-04. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.