Formal models and scripts: datainput-impls-strings

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

• ByteBuffersDataOutput.copyBytes narrows its long length to a signed int, so a copy of 2 GiB or more (for example Directory.copyFrom into a ByteBuffersDirectory) silently copies nothing or only (int) numBytes bytes (finding LFV-107; repro · finding page)

Files

• bbdo-copybytes-int-truncation/model/copybytes_cast_z3.py (used for LFV-107)

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.