Reduce liquidation penalty

contracts/src/BorrowerOperations.sol

@@ -23,14 +23,17 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  // --- Connected contract declarations ---
 
  IERC20 public immutable ETH;
- ITroveManager public troveManager;
+ ITroveManager public immutable troveManager;
  address stabilityPoolAddress;
  address gasPoolAddress;
  ICollSurplusPool collSurplusPool;
  IBoldToken public boldToken;
  // A doubly linked list of Troves, sorted by their collateral ratios
  ISortedTroves public sortedTroves;
 
+ // Minimum collateral ratio for individual troves
+ uint256 public immutable MCR;
+
  /* --- Variable container structs ---
 
  Used to hold, return and assign variables inside a function, in order to avoid the error:
@@ -101,15 +104,21 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  );
  event BoldBorrowingFeePaid(uint256 indexed _troveId, uint256 _boldFee);
 
- constructor(address _ETHAddress) {
- checkContract(_ETHAddress);
- ETH = IERC20(_ETHAddress);
+ constructor(IERC20 _ETH, ITroveManager _troveManager) {
+ checkContract(address(_ETH));
+ checkContract(address(_troveManager));
+
+ ETH = _ETH;
+ troveManager = _troveManager;
+
+ MCR = _troveManager.MCR();
+
+ emit TroveManagerAddressChanged(address(_troveManager));
  }
 
  // --- Dependency setters ---
 
  function setAddresses(
- address _troveManagerAddress,
  address _activePoolAddress,
  address _defaultPoolAddress,
  address _stabilityPoolAddress,
@@ -122,7 +131,6 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  // This makes impossible to open a trove with zero withdrawn Bold
  assert(MIN_NET_DEBT > 0);
 
- checkContract(_troveManagerAddress);
  checkContract(_activePoolAddress);
  checkContract(_defaultPoolAddress);
  checkContract(_stabilityPoolAddress);
@@ -132,7 +140,6 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  checkContract(_sortedTrovesAddress);
  checkContract(_boldTokenAddress);
 
- troveManager = ITroveManager(_troveManagerAddress);
  activePool = IActivePool(_activePoolAddress);
  defaultPool = IDefaultPool(_defaultPoolAddress);
  stabilityPoolAddress = _stabilityPoolAddress;
@@ -142,7 +149,6 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  sortedTroves = ISortedTroves(_sortedTrovesAddress);
  boldToken = IBoldToken(_boldTokenAddress);
 
- emit TroveManagerAddressChanged(_troveManagerAddress);
  emit ActivePoolAddressChanged(_activePoolAddress);
  emit DefaultPoolAddressChanged(_defaultPoolAddress);
  emit StabilityPoolAddressChanged(_stabilityPoolAddress);
@@ -278,7 +284,7 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  // TODO: Use oldDebt and assert in fuzzing, remove before deployment
  uint256 oldDebt = troveManager.getTroveEntireDebt(_troveId);
  _adjustTrove(msg.sender, _troveId, 0, false, _boldAmount, false, 0, contractsCache);
- assert(troveManager.getTroveEntireDebt(_troveId) < oldDebt); 
+ assert(troveManager.getTroveEntireDebt(_troveId) < oldDebt);
  }
 
  function adjustTrove(
@@ -292,12 +298,19 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  ContractsCacheTMAPBT memory contractsCache = ContractsCacheTMAPBT(troveManager, activePool, boldToken);
  _requireTroveIsActive(contractsCache.troveManager, _troveId);
  _adjustTrove(
- msg.sender, _troveId, _collChange, _isCollIncrease, _boldChange, _isDebtIncrease, _maxFeePercentage, contractsCache
+ msg.sender,
+ _troveId,
+ _collChange,
+ _isCollIncrease,
+ _boldChange,
+ _isDebtIncrease,
+ _maxFeePercentage,
+ contractsCache
  );
  }
 
  function adjustUnredeemableTrove(
-  uint256 _troveId,
+ uint256 _troveId,
  uint256 _maxFeePercentage,
  uint256 _collChange,
  bool _isCollIncrease,
@@ -308,12 +321,21 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  ) external override {
  ContractsCacheTMAPBT memory contractsCache = ContractsCacheTMAPBT(troveManager, activePool, boldToken);
  _requireTroveIsUnredeemable(contractsCache.troveManager, _troveId);
-  // TODO: Gas - pass the cached TM down here, since we fetch it again inside _adjustTrove?
+ // TODO: Gas - pass the cached TM down here, since we fetch it again inside _adjustTrove?
  _adjustTrove(
- msg.sender, _troveId, _collChange, _isCollIncrease, _boldChange, _isDebtIncrease, _maxFeePercentage, contractsCache
+ msg.sender,
+ _troveId,
+ _collChange,
+ _isCollIncrease,
+ _boldChange,
+ _isDebtIncrease,
+ _maxFeePercentage,
+ contractsCache
  );
  troveManager.setTroveStatusToActive(_troveId);
- sortedTroves.insert(_troveId, contractsCache.troveManager.getTroveAnnualInterestRate(_troveId), _upperHint, _lowerHint);
+ sortedTroves.insert(
+ _troveId, contractsCache.troveManager.getTroveAnnualInterestRate(_troveId), _upperHint, _lowerHint
+ );
  }
 
  function adjustTroveInterestRate(
@@ -545,11 +567,9 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  /**
  * Claim remaining collateral from a redemption or from a liquidation with ICR > MCR in Recovery Mode
  */
- function claimCollateral(uint256 _troveId) external override {
- _requireIsOwner(_troveId);
-
+ function claimCollateral() external override {
  // send ETH from CollSurplus Pool to owner
- collSurplusPool.claimColl(msg.sender, _troveId);
+ collSurplusPool.claimColl(msg.sender);
  }
 
  // --- Helper functions ---
@@ -632,17 +652,19 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  uint256 _boldChange,
  bool _isDebtIncrease
  ) internal {
- if (_isDebtIncrease) { // implies _boldChange > 0
+ if (_isDebtIncrease) {
+ // implies _boldChange > 0
  address borrower = _troveManager.ownerOf(_troveId);
  _boldToken.mint(borrower, _boldChange);
- } else if (_boldChange > 0 ){
+ } else if (_boldChange > 0) {
  _boldToken.burn(msg.sender, _boldChange);
  }
 
- if (_isCollIncrease) { // implies _collChange > 0
+ if (_isCollIncrease) {
+ // implies _collChange > 0
  // Pull ETH tokens from sender and move them to the Active Pool
  _pullETHAndSendToActivePool(_activePool, _collChange);
- } else if (_collChange > 0 ){
+ } else if (_collChange > 0) {
  address borrower = _troveManager.ownerOf(_troveId);
  // Pull ETH from Active Pool and decrease its recorded ETH balance
  _activePool.sendETH(borrower, _collChange);
@@ -709,11 +731,13 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  }
 
  function _requireTroveIsUnredeemable(ITroveManager _troveManager, uint256 _troveId) internal view {
- require(_troveManager.checkTroveIsUnredeemable(_troveId), "BorrowerOps: Trove does not have unredeemable status");
+ require(
+ _troveManager.checkTroveIsUnredeemable(_troveId), "BorrowerOps: Trove does not have unredeemable status"
+ );
  }
 
- function _requireTroveIsNotOpen(ITroveManager _troveManager, uint256 _troveId) internal view { 
- require(!_troveManager.checkTroveIsOpen(_troveId),"BorrowerOps: Trove is open");
+ function _requireTroveIsNotOpen(ITroveManager _troveManager, uint256 _troveId) internal view {
+ require(!_troveManager.checkTroveIsOpen(_troveId), "BorrowerOps: Trove is open");
  }
 
  function _requireNonZeroCollChange(uint256 _collChange) internal pure {
@@ -770,7 +794,7 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  }
  }
 
- function _requireICRisAboveMCR(uint256 _newICR) internal pure {
+ function _requireICRisAboveMCR(uint256 _newICR) internal view {
  require(_newICR >= MCR, "BorrowerOps: An operation that would result in ICR < MCR is not permitted");
  }
 

contracts/src/CollSurplusPool.sol

@@ -6,9 +6,8 @@ import "openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol";
 
 import "./Interfaces/ICollSurplusPool.sol";
 import "./Dependencies/Ownable.sol";
-import "./Dependencies/CheckContract.sol";
 
-contract CollSurplusPool is Ownable, CheckContract, ICollSurplusPool {
+contract CollSurplusPool is Ownable, ICollSurplusPool {
  using SafeERC20 for IERC20;
 
  string public constant NAME = "CollSurplusPool";
@@ -21,19 +20,18 @@ contract CollSurplusPool is Ownable, CheckContract, ICollSurplusPool {
  // deposited ether tracker
  uint256 internal ETHBalance;
  // Collateral surplus claimable by trove owners
- mapping(uint256 => uint256) internal balances;
+ mapping(address => uint256) internal balances;
 
  // --- Events ---
 
  event BorrowerOperationsAddressChanged(address _newBorrowerOperationsAddress);
  event TroveManagerAddressChanged(address _newTroveManagerAddress);
  event ActivePoolAddressChanged(address _newActivePoolAddress);
 
- event CollBalanceUpdated(uint256 indexed _troveId, uint256 _newBalance);
+ event CollBalanceUpdated(address indexed _account, uint256 _newBalance);
  event EtherSent(address _to, uint256 _amount);
 
  constructor(address _ETHAddress) {
- checkContract(_ETHAddress);
  ETH = IERC20(_ETHAddress);
  }
 
@@ -44,10 +42,6 @@ contract CollSurplusPool is Ownable, CheckContract, ICollSurplusPool {
  override
  onlyOwner
  {
- checkContract(_borrowerOperationsAddress);
- checkContract(_troveManagerAddress);
- checkContract(_activePoolAddress);
-
  borrowerOperationsAddress = _borrowerOperationsAddress;
  troveManagerAddress = _troveManagerAddress;
  activePoolAddress = _activePoolAddress;
@@ -65,29 +59,29 @@ contract CollSurplusPool is Ownable, CheckContract, ICollSurplusPool {
  return ETHBalance;
  }
 
- function getCollateral(uint256 _troveId) external view override returns (uint256) {
- return balances[_troveId];
+ function getCollateral(address _account) external view override returns (uint256) {
+ return balances[_account];
  }
 
  // --- Pool functionality ---
 
- function accountSurplus(uint256 _troveId, uint256 _amount) external override {
+ function accountSurplus(address _account, uint256 _amount) external override {
  _requireCallerIsTroveManager();
 
- uint256 newAmount = balances[_troveId] + _amount;
- balances[_troveId] = newAmount;
+ uint256 newAmount = balances[_account] + _amount;
+ balances[_account] = newAmount;
  ETHBalance = ETHBalance + _amount;
 
- emit CollBalanceUpdated(_troveId, newAmount);
+ emit CollBalanceUpdated(_account, newAmount);
  }
 
- function claimColl(address _account, uint256 _troveId) external override {
+ function claimColl(address _account) external override {
  _requireCallerIsBorrowerOperations();
- uint256 claimableColl = balances[_troveId];
+ uint256 claimableColl = balances[_account];
  require(claimableColl > 0, "CollSurplusPool: No collateral available to claim");
 
- balances[_troveId] = 0;
- emit CollBalanceUpdated(_troveId, 0);
+ balances[_account] = 0;
+ emit CollBalanceUpdated(_account, 0);
 
  ETHBalance = ETHBalance - claimableColl;
  emit EtherSent(_account, claimableColl);

contracts/src/CollateralRegistry.sol

@@ -118,7 +118,9 @@ contract CollateralRegistry is LiquityBase, ICollateralRegistry {
  uint256 redeemedAmount;
  }
 
- function redeemCollateral(uint256 _boldAmount, uint256 _maxIterationsPerCollateral, uint256 _maxFeePercentage) external {
+ function redeemCollateral(uint256 _boldAmount, uint256 _maxIterationsPerCollateral, uint256 _maxFeePercentage)
+ external
+ {
  _requireValidMaxFeePercentage(_maxFeePercentage);
  _requireAmountGreaterThanZero(_boldAmount);
  _requireBoldBalanceCoversRedemption(boldToken, msg.sender, _boldAmount);
@@ -135,7 +137,8 @@ contract CollateralRegistry is LiquityBase, ICollateralRegistry {
  // We only compute it here, and update it at the end,
  // because the final redeemed amount may be less than the requested amount
  // Redeemers should take this into account in order to request the optimal amount to not overpay
- uint256 redemptionRate = _calcRedemptionRate(_getUpdatedBaseRateFromRedemption(_boldAmount, totals.boldSupplyAtStart));
+ uint256 redemptionRate =
+ _calcRedemptionRate(_getUpdatedBaseRateFromRedemption(_boldAmount, totals.boldSupplyAtStart));
  require(redemptionRate <= _maxFeePercentage, "CR: Fee exceeded provided maximum");
  // Implicit by the above and the _requireValidMaxFeePercentage checks
  //require(newBaseRate < DECIMAL_PRECISION, "CR: Fee would eat up all collateral");
@@ -195,9 +198,7 @@ contract CollateralRegistry is LiquityBase, ICollateralRegistry {
  }
 
  // Updates the `baseRate` state with math from `_getUpdatedBaseRateFromRedemption`
- function _updateBaseRateAndGetRedemptionRate(uint256 _boldAmount, uint256 _totalBoldSupplyAtStart)
- internal
- {
+ function _updateBaseRateAndGetRedemptionRate(uint256 _boldAmount, uint256 _totalBoldSupplyAtStart) internal {
  uint256 newBaseRate = _getUpdatedBaseRateFromRedemption(_boldAmount, _totalBoldSupplyAtStart);
 
  //assert(newBaseRate <= DECIMAL_PRECISION); // This is already enforced in `_getUpdatedBaseRateFromRedemption`

contracts/src/Dependencies/LiquityBase.sol

@@ -20,9 +20,6 @@ contract LiquityBase is BaseMath, ILiquityBase {
 
  uint256 public constant _100pct = 1000000000000000000; // 1e18 == 100%
 
- // Minimum collateral ratio for individual troves
- uint256 public constant MCR = 1100000000000000000; // 110%
-
  // Critical system collateral ratio. If the system's total collateral ratio (TCR) falls below the CCR, Recovery Mode is triggered.
  uint256 public constant CCR = 1500000000000000000; // 150%
 

contracts/src/Dependencies/LiquityMath.sol

@@ -13,6 +13,10 @@ library LiquityMath {
  return (_a >= _b) ? _a : _b;
  }
 
+ function _sub_min_0(uint256 _a, uint256 _b) internal pure returns (uint256) {
+ return (_a > _b) ? _a - _b : 0;
+ }
+
  /* 
  * Multiply two decimal numbers and use normal rounding rules:
  * -round product up if 19'th mantissa digit >= 5

contracts/src/HintHelpers.sol

@@ -69,7 +69,7 @@ contract HintHelpers is LiquityBase, Ownable, CheckContract {
  uint256 currentId = troveManager.getTroveFromTroveIdsArray(arrayIndex);
 
  // Skip this Trove if it's unredeeamable and not in the sorted list
- if (!sortedTroves.contains(currentId)) { continue; }
+ if (!sortedTroves.contains(currentId)) continue;
 
  uint256 currentInterestRate = troveManager.getTroveAnnualInterestRate(currentId);
 

contracts/src/Interfaces/IBorrowerOperations.sol

@@ -13,7 +13,6 @@ interface IBorrowerOperations is ILiquityBase {
  function sortedTroves() external view returns (ISortedTroves);
 
  function setAddresses(
- address _troveManagerAddress,
  address _activePoolAddress,
  address _defaultPoolAddress,
  address _stabilityPoolAddress,
@@ -57,7 +56,7 @@ interface IBorrowerOperations is ILiquityBase {
  ) external;
 
  function adjustUnredeemableTrove(
-  uint256 _troveId,
+ uint256 _troveId,
  uint256 _maxFeePercentage,
  uint256 _collChange,
  bool _isCollIncrease,
@@ -66,8 +65,8 @@ interface IBorrowerOperations is ILiquityBase {
  uint256 _upperHint,
  uint256 _lowerHint
  ) external;
- 
- function claimCollateral(uint256 _troveId) external;
+
+ function claimCollateral() external;
 
  function setAddManager(uint256 _troveId, address _manager) external;
  function setRemoveManager(uint256 _troveId, address _manager) external;

contracts/src/Interfaces/ICollSurplusPool.sol

@@ -8,9 +8,9 @@ interface ICollSurplusPool {
 
  function getETHBalance() external view returns (uint256);
 
- function getCollateral(uint256 _troveId) external view returns (uint256);
+ function getCollateral(address _account) external view returns (uint256);
 
- function accountSurplus(uint256 _troveId, uint256 _amount) external;
+ function accountSurplus(address _account, uint256 _amount) external;
 
- function claimColl(address _account, uint256 _troveId) external;
+ function claimColl(address _account) external;
 }

contracts/src/Interfaces/ILiquityBase.sol

@@ -12,6 +12,5 @@ interface ILiquityBase {
  function priceFeed() external view returns (IPriceFeed);
  function BOLD_GAS_COMPENSATION() external view returns (uint256);
  function MIN_NET_DEBT() external view returns (uint256);
- function MCR() external view returns (uint256);
  function getEntireSystemDebt() external view returns (uint256);
 }

contracts/src/Interfaces/ITroveManager.sol

@@ -11,6 +11,8 @@ import "./ISortedTroves.sol";
 
 // Common interface for the Trove Manager.
 interface ITroveManager is IERC721, ILiquityBase {
+ function MCR() external view returns (uint256);
+
  function setAddresses(
  address _borrowerOperationsAddress,
  address _activePoolAddress,