fix: filter for empty attestations when pulling from block

[Maddiaa0]

Overview

Attestations can be empty if not received, filter them before pulling from block

[Maddiaa0]

• fix: filter for empty attestations when pulling from block #12740 👈 (View in Graphite)
• master

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[spalladino]

Thanks for catching this. Curious: when is a signature empty? Shouldn't it be rejected by the Rollup contract? Or is it temporary?

[Maddiaa0]

Thanks for catching this. Curious: when is a signature empty? Shouldn't it be rejected by the Rollup contract? Or is it temporary?

The signatures of the committee are checked in order, and if we do not have a signature, we check for empty. This is rather than looking up the committee for their addresses one by one. Its more gas efficient to do at the expense of calldata, like alot of things, this is up for change / fix come the gas reaper.

    bytes32 digest = _digest.toEthSignedMessageHash();
    for (uint256 i = 0; i < _signatures.length; i++) {
      // To avoid stack too deep errors
      Signature memory signature = _signatures[i];
      if (signature.isEmpty) {
        continue;
      }

      // The verification will throw if invalid
      signature.verify(committee[i], digest);  /////////////// rather than have a reverse lookup of address to committee index
      validAttestations++;
    }