[julianlen]

Description

We decided to drop the grace period for the pegout tx index after RSKIP643. A release created before RSKIP643 is only recorded in the pegout tx index, by sighash. A release created after it has its outputs to the live federations stored in federationsPendingBtcUTXOs. registerBtcTransaction now recognises both kinds at any BTC height, so there is no longer a height at which the Bridge stops looking up the pegout tx index.

This PR removes what was left of the grace period:

• PegUtils.isFederationsPendingBtcUTXOsEnabled, which nothing called anymore.
• btcHeightWhenFederationsPendingBtcUTXOsActivates and its getter from BridgeConstants, plus the placeholder values in the mainnet, testnet, testnet2 and regtest constants.

Production behaviour is the same as on the base branch. With RSKIP643 active, registerBtcTransaction handles releases like this:

Release	Registered after RSKIP643
Created for Vetiver, only in the pegout tx index	PEGOUT_OR_MIGRATION, outputs to the live federations are registered
Created for Cardamom, in federationsPendingBtcUTXOs	processed through registerNewUTXOsByTxIdAndMarkTxHashAsProcessed

Motivation and Context

How Has This Been Tested?

• BridgeSupportRegisterBtcTransactionTest
  • Pegouts with and without change, and migrations, created for Vetiver and created for Cardamom, all registered with every activation enabled. Vetiver releases register at HEIGHT_AT_WHICH_TO_START_USING_PEGOUT_INDEX. Cardamom releases register at HEIGHT_TO_USE_FEDERATIONS_PENDING_BTC_UTXOS, 100 blocks later.
  • New forVetiver cases for segwit pegouts and migrations in PegoutTransaction and MigrationTransaction.
  • A tx with change to the federation that is not in the pegout tx index is still rejected as a legacy pegin and refunded.
• BridgeSupportSvpTest: the SVP fund tx created for Vetiver and created for Cardamom, registered while the SVP is ongoing and after its values were cleared.
• BridgeConstantsTest: removed the getBtcHeightWhenFederationsPendingBtcUTXOsActivates test together with the constant.
• PegUtilsTest: readability only, with static imports for PegTxType and one argument per line.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• Tests for the changes have been added (for bug fixes / features)
• Requires Activation Code (Hard Fork)

• Other information:
  Gated by RSKIP643. The mainnet/testnet btcHeightWhenFederationsPendingBtcUTXOsActivates values on the base branch are placeholders (10_000_000) until the activation is scheduled.

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[Copilot]

🟡 Changes recommended

Existing legacy-release registration tests still expect processing at heights beyond the new cutoff.

1 open issue

• Update legacy release test for the new pegout cutoff · New

What changed in this PR

Updates bridge transaction classification to stop consulting the legacy pegout index after the RSKIP643 grace period.

Changes:

• Passes bridge constants and BTC transaction height into classification.
• Skips sighash computation and index lookup after the cutoff.
• Adds grace-period classification tests for pegouts and migrations.

File	Description
rskj-core/​src/​test/​java/​co/​rsk/​peg/​PegUtilsTest.java	Updates classifier calls and tests grace-period boundaries.
rskj-core/​src/​main/​java/​co/​rsk/​peg/​PegUtils.java	Gates legacy index lookup on the RSKIP643 cutoff.

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Consensus-sensitive bridge classification and documented placeholder activation heights require final human validation.

1 open issue

• Update legacy release test for the new pegout cutoff

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Consensus-sensitive release classification requires domain-owner validation of the cutoff heights and consequences for older release funds.

1 open issue

• Update legacy release test for the new pegout cutoff

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Consensus-critical bridge classification and activation boundaries require final human validation with passing test results.

1 open issue

• Update legacy release test for the new pegout cutoff

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

The consensus-sensitive change to legacy-release recognition needs human validation of activation thresholds and fund-registration behavior.

1 open issue

• Update legacy release test for the new pegout cutoff

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

The consensus-sensitive cutoff changes recognition of historical releases and registration of their funds, requiring final human review and confirmation of test results.

1 open issue

• Update legacy release test for the new pegout cutoff

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Consensus-critical changes to release classification and refund behavior at the activation boundary require final review by bridge maintainers.

1 open issue

• Update legacy release test for the new pegout cutoff

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

The cutoff changes consensus-critical handling of federation funds and refunds, requiring final bridge-maintainer review.

No open issues 🎉

_{Review effort: Balanced}

[Copilot]

🟡 Changes recommended

The registration tests do not exercise the intended RSKIP643 cutoff boundary, leaving the consensus-sensitive transition unverified.

1 open issue

• Add tests for RSKIP643 cutoff boundary behavior · New

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

The supplied diff and stated cutoff behavior need human reconciliation before approving this consensus-sensitive bridge change.

1 open issue

• Add tests for RSKIP643 cutoff boundary behavior

_{Review effort: Balanced}

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

🟢 Approval recommended

Production changes remove unused code and constants, and static review found no blocking issues in the accompanying test updates.

1 open issue

• Add tests for RSKIP643 cutoff boundary behavior

_{Review effort: Balanced}