DelegateCallHelper Manual Review Findings

DCH-01M: Incorrect Management of Error Message Decoding

Type	Severity	Location
Logical Fault		DelegateCallHelper.sol:L8-L15

Description:

As evidenced in the original Stack Overflow thread, the error decoding mechanism referenced is only applicable when no custom errors are defined and will fatally fail with an undefined error when attempting to decode custom errors.

Impact:

Debugging error codes from applications compiled post-0.8.0 and with custom errors will potentially fail when attempting to decode the resulting payload.

Example:

Copy
4library DelegateCallHelper {
5    function delegateAndCheckResult(address recipient, bytes memory data) internal returns (bytes memory) {
6        (bool success, bytes memory result) = recipient.delegatecall(data);
7
8        if (!success) {
9            // https://ethereum.stackexchange.com/a/83577
10            if (result.length < 68) revert('DelegateCallHelper: revert with no reason');
11            assembly {
12                result := add(result, 0x04)
13            }
14            revert(abi.decode(result, (string)));
15        }
16
17        return result;
18    }
19}

Recommendation:

We advise an alternative answer to the original thread to be applied instead that properly handles all error types available in the pragma version of the BlazeSwap code.

Alleviation:

The BlazeSwap team evaluated this exhibit and opted to simply bubble-up the error rather than parse it. We consider this solution an adequate alleviation to the exhibit.