Vulnerability Details

In LiquidationBranch.sol, [LogLiquidateAccount](https://github.com/Cyfrin/2025-01-zaros-part-2/blob/35deb3e92b2a32cd304bf61d27e6071ef36e446d/src/perpetuals/branches/LiquidationBranch.sol#L30-L38) is defined as

The LogLiquidateAccount event is [emitted](https://github.com/Cyfrin/2025-01-zaros-part-2/blob/35deb3e92b2a32cd304bf61d27e6071ef36e446d/src/perpetuals/branches/LiquidationBranch.sol#L244-L252) in LiquidationBranch::LiquidateAccounts() after liquidating account's positions

The issue is that the event is emitting [ctx.activeMarketsIds.length](https://github.com/Cyfrin/2025-01-zaros-part-2/blob/35deb3e92b2a32cd304bf61d27e6071ef36e446d/src/perpetuals/branches/LiquidationBranch.sol#L247-L247) which represents the number of open positions/markets the account had [before** liquidation**](https://github.com/Cyfrin/2025-01-zaros-part-2/blob/35deb3e92b2a32cd304bf61d27e6071ef36e446d/src/perpetuals/branches/LiquidationBranch.sol#L168-L168) not after. while the point of the event is to emit amountOfOpenPositions after the liquidations. Since the positions are [cleared](https://github.com/Cyfrin/2025-01-zaros-part-2/blob/35deb3e92b2a32cd304bf61d27e6071ef36e446d/src/perpetuals/branches/LiquidationBranch.sol#L206-L206) during the liquidation process and the [active markets]( https://github.com/Cyfrin/2025-01-zaros-part-2/blob/35deb3e92b2a32cd304bf61d27e6071ef36e446d/src/perpetuals/branches/LiquidationBranch.sol#L210-L210) are updated i.e removed, the emitted value doesn't accurately reflect the final state

Impact

Incorrect value emission could lead to confusion for those consuming the event data who might assume the number represents the final state rather than the initial state. The event should be clear about what exactly it's reporting since zaros also has an offchain element, incorrect data could disrupt operations

Tools Used

Manual Review

Recommendations

track and emit the actual number of active positions remaining after liquidations