fix(nipopow): pack_interlinks key encoding — use first-occurrence position#866
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fix(nipopow): pack_interlinks key encoding — use first-occurrence position#866mwaddip wants to merge 2 commits into
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Adds two tests to ergo-nipopow/src/nipopow_algos.rs covering NipopowAlgos::pack_interlinks: - pack_interlinks_keys_are_first_occurrence_positions: asserts that the ExtensionKV key[1] for each duplicate-run encodes the input-vector index of the run's first element (JVM Ergo encoding), not a sequential distinct-group counter. Test currently FAILS against the pre-fix pack_interlinks which emits sequential ix_distinct_block_ids. - pack_interlinks_empty_returns_empty: pins the no-panic behavior on empty input. Verified empirically against mainnet block 1784124 nipopow proof (captured 2026-05-13): the JVM-compat key encoding makes 11/11 leaf hashes in interlinksProof.indices match against an external TS port. The pre-fix sequential encoding matches only 2/11. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
…ition Replaces the sequential `ix_distinct_block_ids` counter with the input-vector index of each duplicate-run's first element. Matches JVM Ergo's `NipopowAlgos.packInterlinks` (ergoplatform/ergo, `src/main/scala/org/ergoplatform/modifiers/history/popow/NipopowAlgos.scala`) which encodes ExtensionKV keys as `[INTERLINK_VECTOR_PREFIX, position_of_first_occurrence_in_interlinks_vector]`. ## The bug `unpack_interlinks` filters by `key[0] == INTERLINK_VECTOR_PREFIX` only and never reads `key[1]`, so sigma-rust round-trips its own buggy output internally. The divergence is observable only at the Merkle-leaf hash level: a kv-leaf's hash depends on the full kv-bytes including `key[1]`, so a sigma-rust-packed leaf hashes differently from a JVM-packed leaf. Concrete impact: - `PoPowHeader::check_interlinks_proof` FAILS on real mainnet proofs because the expected Merkle root it computes (via the buggy pack) doesn't match the root the proof's walk-up reaches (built from JVM-packed leaves). - `NipopowProof::is_better_than` rejects all real mainnet proofs as "invalid" because it calls `is_valid()` → `has_valid_proofs()` → `check_interlinks_proof`, which fails for any block with at least one duplicate-run starting past position 1 (≈ every mainnet block). ## Validation Verified against mainnet block 1784124 nipopow proof (captured 2026-05-13 via ergo-node-rust): with this fix, all 11 leaf hashes in the proof's interlinksProof.indices match the JVM-generated leaves exactly. Pre-fix matches only 2 (positions 0 and 1 happen to align because distinct_ix=0,1 also = first_pos=0,1 for the first two runs). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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… landed) Sigma-rust upstream PR ergoplatform/sigma-rust#866 landed 2026-05-19 and was cherry-picked to integration/ergots (worktree HEAD 6ba9d524). Our fixture-gen now uses NipopowAlgos::pack_interlinks / PoPowHeader:: check_interlinks_proof / NipopowProof::is_better_than directly. ### Equivalence test (passed before removal) After reverting all 9 call sites in fixture-gen but BEFORE deleting the JVM-compat module, ran cargo run --release → all regenerated fixture JSON files byte-identical to committed → proves patched sigma-rust output matches our prior JVM-compat workaround exactly. ### Changes - fixture-gen/src/cmds/interlinks_jvm.rs: DELETED - fixture-gen/src/cmds/mod.rs: removed `pub mod interlinks_jvm;` - 9 call sites reverted to sigma-rust APIs across batch_merkle.rs, compare.rs, nipopow_proof.rs, popow_header.rs - packages/nipopow/src/merkle.ts: packInterlinks JSDoc updated (code unchanged — was already JVM-compat; now agrees with patched upstream) - facts/nipopow.md: removed "sigma-rust divergences" subsection; kept only the unrelated extensionRoot-anchoring known limitation - docs/specs/2026-05-19-sigma-rust-pack-interlinks-upstream-prompt.md: marked SUPERSEDED with PR #866 link; kept for historical context 313 nipopow + 140 avltree + 2658 ergoscript = 3111 tests still pass. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Picks up PR ergoplatform/sigma-rust#866 cherry-picked onto ergo-node-integration — `pack_interlinks` now encodes each kv-pair's `key[1]` as the input-vector index of each duplicate-run's first element, matching the JVM. Pre-fix sigma-rust used a sequential distinct-group counter, so `check_interlinks_proof` rejected every real-mainnet proof. Effect on this node: light-bootstrap's KMZ17 §4.3 multi-peer comparison via `is_better_than` now actually compares proofs. Pre-fix behavior was silent degradation to "first valid proof wins" because every challenger comparison errored. Full-mode operators unaffected — they never run light bootstrap. Workspace builds clean, tests pass. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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pack_interlinks encodes ExtensionKV.key[1] as a sequential distinct-group counter; JVM uses the input-vector index of each duplicate-run's first element. The mismatch is invisible internally (unpack ignores key[1]) but Merkle leaves hash differently from JVM, so check_interlinks_proof and is_better_than reject every real mainnet proof.
Verified against mainnet block 1784124: 11/11 leaf hashes match JVM post-fix (2/11 pre-fix). Also fixes panic on empty input.