wave5: LockTime::ZERO/Sequence::MAX canonicalization + double_sha256 dedup

[metaphorics]

Summary

Wave-5 of the aggressive-cleanup campaign: canonical-constant consolidation on primitives spellings that survived wave-4's OutPoint::null() pass, plus residual hash/idempotence dedup.

CUT

• ~85× LockTime::from_consensus(0) → LockTime::ZERO (const already existed; from_consensus is identity — byte-identical)
• ~30× Sequence::from_consensus(u32::MAX) / Sequence::from_consensus(0xffff_ffff) → Sequence::MAX (the 0xffff_ffff spelling was a wave-4 miss pattern)
• 2× OutPoint::new(Txid::default(), 0xffff_ffff) → OutPoint::null() (same miss pattern, rpc::handlers::mining + rpc::rest test fixtures)
• 2 local double_sha256 test helpers → bitcoin_rs_primitives::encode::double_sha256 canonical owner (node/tests/crash_recovery.rs — also dropped its now-unused sha2 import; script/tests/segwit_v0_sighash_edges.rs becomes a one-line delegate)
• p2p::block_stager::received_order_contains — .iter().any(|q| q == hash) → VecDeque::contains

KEEP (adversarial verdicts on rejected cuts)

• rpc/src/context.rs:2557 rows.get(0) — rows is sonic_rs::Value, not Vec; Value has no .first()
• utxo/src/shard.rs:170 .iter().any(|t| *t == output.script_pubkey) — script_pubkey is &[u8]; slice::contains can't compare Vec<u8> elements against a slice without alloc
• consensus::verify_block::sha256d — already a thin adapter over encode::double_sha256 returning [u8; 32] for merkle paths
• All unreachable! in primitives/layout.rs, index/block.rs, rpc/rest.rs — named invariants on validated spans, not slop
• 98 .expect() sites in src/ — audit confirmed all are test-mod or test-harness files (zero in prod paths)
• core_vectors.rs .any(|r| r == reason) — non-allocating &String vs &str idiom; Vec<String>::contains would need to_owned()

Zero public-API delta → 0.11.0 stands, no corpus re-pin.

Gates: cargo check --workspace --all-targets clean; cargo clippy -D warnings on all 4 CI profiles (workspace, consensus no-default, chainstate fjall, node fjall+zmq, rpc no-default); cargo fmt --check; tests green for primitives/consensus/utxo/mempool/chain/index/storage (~900 tests).

Link to Devin session: https://app.devin.ai/sessions/7338687e984d465b81e17da443ba16e5
Open in Devin Desktop: https://app.devin.ai/desktop/session/7338687e984d465b81e17da443ba16e5?variant=devin
Requested by: @metaphorics

---

Summary by cubic

Consolidates canonical spellings across the codebase: ~85 LockTime::from_consensus(0) → LockTime::ZERO, ~30 Sequence::from_consensus(u32::MAX)/0xffff_ffff → Sequence::MAX, and two OutPoint::new(Txid::default(), 0xffff_ffff) → OutPoint::null(). Replaces local double_sha256 test helpers with bitcoin_rs_primitives::encode::double_sha256 and swaps .iter().any(...) for VecDeque::contains in p2p::block_stager.

No public API delta; the replaced from_consensus calls are identity functions, so all values are byte-identical.

^{Written for commit 790cecb. Summary will update on new commits.}

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring

---

Original prompt from a

@gosuda/bitcoin-rs @skills:purge-slop-docs @skills:tests-purge-unneeded @skills:code-simplification @skills:tests-adversarial @skills:idiomatic-rust Run extremely aggressive cleanups, test replace to real defects-catching tests(no naive mock or contract test, burn them all), and architectural refactorings.

[chatgpt-codex-connector]

You have reached your Codex usage limits for code reviews. You can see your limits in the Codex usage dashboard.
To continue using code reviews, add credits to your account and enable them for code reviews in your settings.

[coderabbitai]

Warning

Review limit reached

You've used all free OSS reviews for now. Wait for the free limit to reset to keep reviewing this public repository.

Next included review available in 46 minutes.

Check out review usage here.

View limit details

Limit details: You’ve used the included review currently available.

Learn how review limits work.

Review configuration:

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Advanced

Run ID: 8a4c6ffb-12e5-4f7e-80a8-c899636d90da

📥 Commits

Reviewing files that changed from the base of the PR and between 29b408b and 790cecb.

📒 Files selected for processing (40)

• crates/chain/src/regtest_fixture.rs
• crates/chainstate/tests/unit/apply/persistence_tests.rs
• crates/chainstate/tests/unit/durable_replay_tests.rs
• crates/consensus/src/sigops.rs
• crates/consensus/src/verify_block.rs
• crates/consensus/src/verify_tx.rs
• crates/consensus/tests/overhaul_prepared_inputs.rs
• crates/consensus/tests/witness_activation_rules.rs
• crates/consensus/tests/witness_sigop_activation.rs
• crates/consensus/tests/witness_staging_gate.rs
• crates/mempool/src/accounting.rs
• crates/mempool/src/admission.rs
• crates/mempool/src/entry.rs
• crates/mempool/src/orphan.rs
• crates/mempool/tests/admission.rs
• crates/mining/benches/candidate.rs
• crates/mining/src/coordinator/candidate_template_tests.rs
• crates/mining/tests/coinbase_template.rs
• crates/node/src/chain_effects.rs
• crates/node/src/embed.rs
• crates/node/tests/crash_recovery.rs
• crates/node/tests/mining.rs
• crates/node/tests/mining_e2e.rs
• crates/node/tests/overhaul_fee_history.rs
• crates/node/tests/tx_ingress_e2e.rs
• crates/node/tests/unit/state/tests/construction.rs
• crates/node/tests/unit/sync/tests/mod.rs
• crates/node/tests/unit/sync/tests/transitions_7.rs
• crates/node/tests/unit/tx_ingress/tests.rs
• crates/p2p/src/block_stager.rs
• crates/p2p/src/sync/tests.rs
• crates/p2p/src/sync/tests/witness_staging_gate.rs
• crates/p2p/src/tx_relay.rs
• crates/rpc/src/context.rs
• crates/rpc/src/esplora/backend.rs
• crates/rpc/src/handlers/mining.rs
• crates/rpc/src/handlers/tx.rs
• crates/rpc/src/rest.rs
• crates/rpc/tests/policy_contract.rs
• crates/script/tests/segwit_v0_sighash_edges.rs

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

Autopilot is currently an internal CodeRabbit preview.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[amazon-q-developer]

This cleanup PR successfully consolidates canonical constants and removes code duplication across the codebase. The changes include:

• Replacing manual constant constructions (LockTime::from_consensus(0), Sequence::from_consensus(u32::MAX)) with canonical constants (LockTime::ZERO, Sequence::MAX, OutPoint::null())
• Removing duplicate double_sha256 implementations in favor of the canonical bitcoin_rs_primitives::encode::double_sha256
• Optimizing collection membership checks to use built-in methods (contains vs iter().any())

All changes maintain functional equivalence while improving code consistency and readability. No defects found.

---

You can now have the agent implement changes and create commits directly on your pull request's source branch. Simply comment with /q followed by your request in natural language to ask the agent to make changes.

---

⚠️ This PR contains more than 30 files. Amazon Q is better at reviewing smaller PRs, and may miss issues in larger changesets.

[cubic-dev-ai]

No issues found across 40 files

_{Re-trigger cubic}