Upgraded Q -> 2 from #37 [1703589922038]

[c4-judge]

Judge has assessed an item in Issue #37 as 2 risk. The relevant finding follows:

[L-02] openPosition() maybe underflow
in openPosition() -> Base.swap()

function openPosition(
    DataStruct.OpenPositionParams calldata params
) public override nonReentrant returns (uint96 lienId, uint256 collateralTo) {

...
(cache.amountSpent, cache.amountReceived) = Base.swap(
cache.tokenFrom,
cache.tokenTo,
params.amountSwap,
@> collateralTo - cache.amountToBorrowed - params.marginTo, // amount needed to meet requirement
DEX_AGGREGATOR,
params.data
);
The formula collateralTo - cache.amountToBorrowed - params.marginTo may underflow.

This is especially true if the user wants to increase token0PremiumPortion, thereby transferring to marginTo.

For example: (price outOfRange) collateralTo = 100 amountToBorrowed = 100 marginTo = 10 (want to set token0PremiumPortion >10%)

collateralTo - amountToBorrowed - marginTo will underflow.

Suggestions:

    (cache.amountSpent, cache.amountReceived) = Base.swap(
        cache.tokenFrom,
        cache.tokenTo,
        params.amountSwap,

•       collateralTo - cache.amountToBorrowed - params.marginTo, // amount needed to meet requirement
  

•      (cache.amountToBorrowed + params.marginTo) > collateralTo ? 0 : (collateralTo - cache.amountToBorrowed - params.marginTo),
        DEX_AGGREGATOR,
        params.data
    );
  

[c4-judge]

0xleastwood marked the issue as duplicate of #44

[c4-judge]

0xleastwood marked the issue as satisfactory