v2.2.1

Fixes

• Compatibility: single-format (HDIFFSF20) diffs that store the payload raw (compression would expand it) no longer carry a stale lzma2 compressType label. Old decoders (HDiffPatch ~4.x, including react-native-update clients in the field) decide whether to decompress from the label alone and failed with hpatch error -4 on such diffs — typically tiny diffs between near-identical bundles. Output is now byte-compatible with 1.x for this case. Applies to diff(), diffWindow(), and diffSingleStream(); diffStream (HDIFF13) was never affected.

Upgrade urgency: high if you generate update diffs with 2.0.3–2.2.0 — a small enough diff generated by those versions fails to apply on all deployed clients that predate the reader-side guard.