truncated-hash-upgrade-opt-in

IN premise

Prefix hash upgrade (16-char truncated SHA-256 to full digest) only occurs when `upgrade_hashes=True` is passed to `check_stale`; without it, truncated hashes produce a warning result with `reason="truncated_hash"`.

Summary

When the system encounters old-style shortened content hashes, it does not silently upgrade them to full-length hashes by default. Instead, it flags them as stale with a specific reason code, and only performs the actual upgrade if the caller explicitly opts in. This means existing truncated hashes are preserved and visible rather than being quietly replaced, giving callers control over when hash migration happens.

Details

Source

entries/2026/05/05/tests-test_check_stale.md