Finding description and impact

The function require the minimum purchase amount cannot be more than listing amount. Here has a logic issue, if the _listingType is ListingType.PARTIAL all cases will go through this condition no matter hte _minPurchaseAmt is less than _amount or not.

Impact

The check is meaningless here for _minPurchaseAmt could be larger than _amount. The creation of listing of _minPurchaseAmt larger than _amount is gas wasted for it's meaningless.

Proof of Concept

• https://github.com/code-423n4/2024-12-secondswap/blob/214849c3517eb26b31fe194bceae65cb0f52d2c0/contracts/SecondSwap_Marketplace.sol#L252-L255

Recommended mitigation steps

Don't need to check _listingType here. Just compare _minPurchaseAmt and _amount.