miner: fix block number extraction for BlockSigner tx

[gzliudan]

Proposed changes

Previously, the code used binary.BigEndian.Uint64(data[8:40]), which incorrectly read the index and only extracted the highest 8 bytes of the 32-byte left-padded block number, resulting in wrong values (often zero). Now, the code uses new(big.Int).SetBytes(data[4:36]).Uint64() to correctly extract the block number from the proper 32-byte field. This change fixes both the incorrect index and the parsing logic, ensuring accurate block number extraction and correct validation for special transactions.

eg:

when data is e341eaa4000000000000000000000000000000000000000000000000000000000000000f077c098bfe0729811df156252455c1debd1a8e4b7e781d8c7384ea32d15e5021

old(wrong):
data[8:40] is 0000000000000000000000000000000000000000000000000000000f077c098b
blkNumber is 0

new(right):
data[4:36] is 000000000000000000000000000000000000000000000000000000000000000f
blkNumber is 15

Types of changes

What types of changes does your code introduce to XDC network?
Put an ✅ in the boxes that apply

• 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)
• Documentation Update (if none of the other choices apply)
• Regular KTLO or any of the maintaince work. e.g code style
• CICD Improvement

Impacted Components

Which part of the codebase this PR will touch base on,

Put an ✅ in the boxes that apply

• Consensus
• Account
• Network
• Geth
• Smart Contract
• External components
• Not sure (Please specify below)

Checklist

Put an ✅ in the boxes once you have confirmed below actions (or provide reasons on not doing so) that

• 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
• N/A

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

---

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 and usage tips.}

[Copilot]

Pull request overview

This PR fixes a critical bug in block number extraction for BlockSignersBinary special transactions. The original code was reading from the wrong byte offset and only parsing the first 8 bytes of a 32-byte field, often resulting in incorrect values (typically zero). The fix correctly extracts the full 32-byte block number field and interprets it as a big-endian integer.

Key Changes:

• Corrected byte slice from data[8:40] to data[4:36] to properly extract the 32-byte block number field
• Changed parsing from binary.BigEndian.Uint64() (8-byte read) to new(big.Int).SetBytes().Uint64() (full 32-byte interpretation)
• Removed unused encoding/binary import

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.