Release Notes - v0.202.9

v0.202.9

Title: Improve transaction replay, validation, and decoding safety

Version: v0.202.9

This release improves transaction replay compatibility, ledger-consistent validation, binary decoding safety, signature validation, and collateral rules across supported ledger eras.

💪 Improvements

• Improved redeemer lookup consistency: AlonzoRedeemers.Iter now collapses duplicate (Tag, Index) keys with last-wins semantics, and Value returns the last matching entry. Babbage and legacy Conway handling inherit these semantics, supporting compatible transaction replay.

• Corrected execution unit accounting: ExUnits totals now sum the collapsed redeemer view, so duplicate keys count once while raw redeemer bytes remain available for script-data hashes. Resource accounting now follows the same duplicate-key semantics without changing the bytes used for hashes.

• Standardized transaction size and fee validation: Shelley through Dijkstra now use common.TxSize for maximum transaction size checks and fee measurement. Transactions at the exact size limit now validate consistently, and size-related errors report the correct measurement.

• Hardened binary decoding safety: StreamDecoder.Advance now guards against overflow and out-of-bounds movement, ArrayHeaderSize handles the 32-bit boundary correctly, and zero-value LazyValue methods are safe to call. These changes make decoding more robust at boundary conditions.

• Strengthened consensus-safe signatures: SumKES leaf verification now requires canonical Ed25519 encodings and rejects malformed encodings, small-order points, and non-canonical scalars. This prevents invalid signatures from passing consensus checks.

• Aligned collateral validation with phase-2 execution: Collateral witness and total collateral equality rules now apply only when phase-2 redeemers exist, including redeemers in sub-transaction witness sets. This matches collateral requirements to transactions that use phase-2 redeemers.

Recommended Network Compatibility ⚠️

Network	Compatible
mainnet	⛔
preprod-testnet	✅
preview-testnet	✅
musashi	✅

Release: v0.202.9

Compare: v0.202.8…v0.202.9

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Docs authored by Doc Holiday