Various changes to code clarity (Fix N-07)

contracts/account/utils/draft-ERC4337Utils.sol

@@ -24,9 +24,9 @@ library ERC4337Utils {
     function parseValidationData(
         uint256 validationData
     ) internal pure returns (address aggregator, uint48 validAfter, uint48 validUntil) {
-        validAfter = uint48(bytes32(validationData).extract_32_6(0x00));
-        validUntil = uint48(bytes32(validationData).extract_32_6(0x06));
-        aggregator = address(bytes32(validationData).extract_32_20(0x0c));
+        validAfter = uint48(bytes32(validationData).extract_32_6(0));
+        validUntil = uint48(bytes32(validationData).extract_32_6(6));
+        aggregator = address(bytes32(validationData).extract_32_20(12));
         if (validUntil == 0) validUntil = type(uint48).max;
     }
 
@@ -100,22 +100,22 @@ library ERC4337Utils {
 
     /// @dev Returns `verificationGasLimit` from the {PackedUserOperation}.
     function verificationGasLimit(PackedUserOperation calldata self) internal pure returns (uint256) {
-        return uint128(self.accountGasLimits.extract_32_16(0x00));
+        return uint128(self.accountGasLimits.extract_32_16(0));
     }
 
     /// @dev Returns `accountGasLimits` from the {PackedUserOperation}.
     function callGasLimit(PackedUserOperation calldata self) internal pure returns (uint256) {
-        return uint128(self.accountGasLimits.extract_32_16(0x10));
+        return uint128(self.accountGasLimits.extract_32_16(16));
     }
 
     /// @dev Returns the first section of `gasFees` from the {PackedUserOperation}.
     function maxPriorityFeePerGas(PackedUserOperation calldata self) internal pure returns (uint256) {
-        return uint128(self.gasFees.extract_32_16(0x00));
+        return uint128(self.gasFees.extract_32_16(0));
     }
 
     /// @dev Returns the second section of `gasFees` from the {PackedUserOperation}.
     function maxFeePerGas(PackedUserOperation calldata self) internal pure returns (uint256) {
-        return uint128(self.gasFees.extract_32_16(0x10));
+        return uint128(self.gasFees.extract_32_16(16));
     }
 
     /// @dev Returns the total gas price for the {PackedUserOperation} (ie. `maxFeePerGas` or `maxPriorityFeePerGas + basefee`).

contracts/governance/utils/VotesExtended.sol

@@ -13,8 +13,8 @@ abstract contract VotesExtended is Votes {
     using Checkpoints for Checkpoints.Trace160;
     using Checkpoints for Checkpoints.Trace208;
 
-    mapping(address delegator => Checkpoints.Trace160) private _delegateCheckpoints;
-    mapping(address account => Checkpoints.Trace208) private _balanceOfCheckpoints;
+    mapping(address delegator => Checkpoints.Trace160) private _userDelegationCheckpoints;
+    mapping(address account => Checkpoints.Trace208) private _userVotingWeightCheckpoints;
 
     /**
      * @dev Returns the delegate of an `account` at a specific moment in the past. If the `clock()` is
@@ -29,7 +29,7 @@ abstract contract VotesExtended is Votes {
         if (timepoint >= currentTimepoint) {
             revert ERC5805FutureLookup(timepoint, currentTimepoint);
         }
-        return address(_delegateCheckpoints[account].upperLookupRecent(timepoint.toUint48()));
+        return address(_userDelegationCheckpoints[account].upperLookupRecent(timepoint.toUint48()));
     }
 
     /**
@@ -45,25 +45,25 @@ abstract contract VotesExtended is Votes {
         if (timepoint >= currentTimepoint) {
             revert ERC5805FutureLookup(timepoint, currentTimepoint);
         }
-        return _balanceOfCheckpoints[account].upperLookupRecent(timepoint.toUint48());
+        return _userVotingWeightCheckpoints[account].upperLookupRecent(timepoint.toUint48());
     }
 
     /// @inheritdoc Votes
     function _delegate(address account, address delegatee) internal virtual override {
         super._delegate(account, delegatee);
 
-        _delegateCheckpoints[account].push(clock(), uint160(delegatee));
+        _userDelegationCheckpoints[account].push(clock(), uint160(delegatee));
     }
 
     /// @inheritdoc Votes
     function _transferVotingUnits(address from, address to, uint256 amount) internal virtual override {
         super._transferVotingUnits(from, to, amount);
         if (from != to) {
             if (from != address(0)) {
-                _balanceOfCheckpoints[from].push(clock(), _getVotingUnits(from).toUint208());
+                _userVotingWeightCheckpoints[from].push(clock(), _getVotingUnits(from).toUint208());
             }
             if (to != address(0)) {
-                _balanceOfCheckpoints[to].push(clock(), _getVotingUnits(to).toUint208());
+                _userVotingWeightCheckpoints[to].push(clock(), _getVotingUnits(to).toUint208());
             }
         }
     }

contracts/proxy/Clones.sol

@@ -227,9 +227,9 @@ library Clones {
      *   function should only be used to check addresses that are known to be clones.
      */
     function fetchCloneArgs(address instance) internal view returns (bytes memory) {
-        bytes memory result = new bytes(instance.code.length - 0x2d); // revert if length is too short
+        bytes memory result = new bytes(instance.code.length - 45); // revert if length is too short
         assembly ("memory-safe") {
-            extcodecopy(instance, add(result, 0x20), 0x2d, mload(result))
+            extcodecopy(instance, add(result, 0x20), 45, mload(result))
         }
         return result;
     }
@@ -248,11 +248,11 @@ library Clones {
         address implementation,
         bytes memory args
     ) private pure returns (bytes memory) {
-        if (args.length > 0x5fd3) revert CloneArgumentsTooLong();
+        if (args.length > 24531) revert CloneArgumentsTooLong();
         return
             abi.encodePacked(
                 hex"61",
-                uint16(args.length + 0x2d),
+                uint16(args.length + 45),
                 hex"3d81600a3d39f3363d3d373d3d3d363d73",
                 implementation,
                 hex"5af43d82803e903d91602b57fd5bf3",

contracts/utils/NoncesKeyed.sol

@@ -7,6 +7,10 @@ import {Nonces} from "./Nonces.sol";
  * @dev Alternative to {Nonces}, that supports key-ed nonces.
  *
  * Follows the https://eips.ethereum.org/EIPS/eip-4337#semi-abstracted-nonce-support[ERC-4337's semi-abstracted nonce system].
+ *
+ * Note: This contract extends {Nonces}, and reuses {Nonces}'s storage for key #0. This makes upgrading from {Nonces}
+ * to {NoncesKeyed} safe, as such an upgrade will NOT reset the current state of nonces. Doing otherwise would enable
+ * replay attacks where operation that used nonces before the upgrade would be replayable after the upgrade.
  */
 abstract contract NoncesKeyed is Nonces {
     mapping(address owner => mapping(uint192 key => uint64)) private _nonces;