core/txpool/legacypool: reject gapped tx from delegated account #31430

[gzliudan]

Proposed changes

Ref: ethereum#31430

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• Bugfix (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)
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• Regular KTLO or any of the maintaince work. e.g code style
• CICD Improvement

Impacted Components

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• Consensus
• Account
• Network
• Geth
• Smart Contract
• External components
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Checklist

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• This PR has sufficient test coverage (unit/integration test) OR I have provided reason in the PR description for not having test coverage
• Provide an end-to-end test plan in the PR description on how to manually test it on the devnet/testnet.
• Tested the backwards compatibility.
• Tested with XDC nodes running this version co-exist with those running the previous version.
• Relevant documentation has been updated as part of this PR
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[Copilot]

Pull request overview

This PR implements EIP-7702 delegation support by adding restrictions on transactions from delegated accounts and introducing a lazy transaction loading mechanism. The main purpose is to prevent transaction churn attacks on delegated accounts by limiting them to one in-flight transaction at a time.

Key changes include:

• Refactored transaction ordering logic from core/types package to miner package with support for LazyTransaction wrapper
• Added address reservation mechanism in transaction pool to ensure subpool exclusivity
• Implemented delegation and authorization tracking to enforce single-transaction limits on delegated accounts

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
miner/ordering.go	New file containing transaction ordering logic moved from core/types, now using LazyTransaction
miner/ordering_test.go	New test file with comprehensive tests for transaction ordering, including special transaction separation
miner/worker.go	Updated to use new ordering logic with LazyTransaction wrapper and baseFee parameter
core/types/transaction.go	Removed TransactionsByPriceAndNonce and related heap structures; added SetCodeAuthorities() and Time() methods
core/types/transaction_test.go	Removed ordering tests that were moved to miner package
core/types/tx_setcode.go	Fixed SignSetCode parameter order (prv, auth instead of auth, prv)
core/txpool/txpool.go	Added address reservation mechanism and LazyTransaction support in Pending()
core/txpool/subpool.go	Added LazyTransaction wrapper type and AddressReserver callback; updated SubPool interface
core/txpool/validation.go	Enhanced validation with SetCode transaction checks and UsedAndLeftSlots callback
core/txpool/errors.go	Moved ErrFutureReplacePending to legacypool; added ErrAccountLimitExceeded
core/txpool/legacypool/legacypool.go	Major changes: added delegation limit checking, authority validation, address reservation, and Clear() method
core/txpool/legacypool/legacypool_test.go	Added comprehensive tests for SetCode transactions and delegation scenarios; updated all Init() calls
core/txpool/legacypool/legacypool2_test.go	Updated Init() calls to include makeAddressReserver()
eth/protocol.go	Updated Pending() interface to return LazyTransaction
eth/sync.go	Updated to resolve LazyTransaction when syncing
eth/api_backend.go	Updated to resolve LazyTransaction when retrieving pool transactions
eth/helper_test.go	Updated test helper to return LazyTransaction from Pending()

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[Copilot]

There's a missing nil check after calling lazyTx.Resolve() on line 133. If Resolve() returns nil, or if tx.Tx is nil, this will cause a nil pointer dereference when calling tx.Tx.IsSpecialTransaction(). Consider adding a nil check before accessing the transaction.