FundsBase Code Style Findings

FBE-01C: Inefficient Handling of Dispute Resolution Refund

Type	Severity	Location
Gas Optimization		FundsBase.sol:L253, L254, L258, L274

Description:

The BPIP-8 has introduced a specialized mutualizer address that is meant to handle dispute resolution fee provisions as well as refunds, and this contract has been integrated by the FundsBase::releaseFunds finalization action.

The current integration appears to be inefficient due to two points; firstly, the DisputeResolutionTerms data points are read multiple times inefficiently from storage whereas they should be loaded to memory.

Secondly, the current mechanism will either issue a total refund or no refund at all.

Example:

Copy
252// Return unused DR fee to mutualizer or seller's pool
253if (drTerms.feeAmount != 0) {
254    uint256 returnAmount = drTerms.feeAmount - payoff.disputeResolver;
255
256    // Use exchange-level mutualizer address (locked at commitment time)
257    if (exchange.mutualizerAddress == address(0)) {
258        if (returnAmount > 0) {
259            increaseAvailableFundsAndEmitEvent(
260                _exchangeId,
261                offer.sellerId,
262                exchangeToken,
263                returnAmount,
264                sender
265            );
266        }
267    } else {
268        if (exchangeToken == address(0)) {
269            IDRFeeMutualizer(exchange.mutualizerAddress).returnDRFee{ value: returnAmount }(
270                _exchangeId,
271                returnAmount
272            );
273        } else {
274            if (returnAmount > 0) {
275                IERC20(exchangeToken).safeApprove(exchange.mutualizerAddress, returnAmount);
276            }
277            IDRFeeMutualizer(exchange.mutualizerAddress).returnDRFee(_exchangeId, returnAmount);
278        }
279    }
280}

Recommendation:

We advise the code to be optimized by loading data into memory and by optimizing the if conditional that triggers the refund to drTerms.feeAmount != 0 && payoff.disputeResolver == 0, permitting the code within to omit several conditionals.

Alleviation (efd5d1a8f23c3bca7c25273ea4c912a367250119):

The exhibit was partly addressed by introducing the memory related optimization, however, the Boson Protocol team clarified that zero-value exchange finalizations on the IDRFeeMutualizer should occur to ensure it is informed that no fee was ultimately captured.

As such, we consider this exhibit fully addressed.