Bug fix: kickWithDeposit likely push LUP below HTP affecting healthy loans

docs/Functions.md

@@ -114,27 +114,27 @@
 
 ### transferLP
  external libraries call:
- - LenderActions.transferLP()
+ - LPActions.transferLP()
 
  write state:
- - LenderActions.transferLP():
+ - LPActions.transferLP():
  - delete allowance mapping
  - increment new lender.lps accumulator and lender.depositTime state
  - delete old lender from bucket -> lender mapping
 
  reverts on:
- - LenderActions.transferLP():
+ - LPActions.transferLP():
  - invalid index InvalidIndex()
  - no allowance NoAllowance()
 
  emit events:
- - LenderActions.transferLP():
+ - LPActions.transferLP():
  - TransferLP
 
 ### kick
  external libraries call:
  - PoolCommons.accrueInterest()
- - Auctions.kick()
+ - KickerActions.kick()
  - PoolCommons.updateInterestRate()
 
  write state:
@@ -143,7 +143,7 @@
  - Deposits.mult() (scale Fenwick tree with new interest accrued):
  - update scaling array state 
  - increment reserveAuction.totalInterestEarned accumulator
- - Auctions.kick():
+ - KickerActions.kick():
  - _kick():
  - _recordAuction():
  - borrower -> liquidation mapping update
@@ -164,20 +164,20 @@
  - pool inflator and inflatorUpdate state
 
  reverts on:
- - Auctions.kick():
+ - KickerActions.kick():
  - borrower collateralized BorrowerOk()
  - auction active AuctionActive()
 
  emit events:
- - Auctions.kick():
+ - KickerActions.kick():
  - Kick
  - PoolCommons.updateInterestRate():
  - UpdateInterestRate
 
-### kickWithDeposit
+### lenderKick
  external libraries call:
  - PoolCommons.accrueInterest()
- - Auctions.kickWithDeposit()
+ - KickerActions.lenderKick()
  - PoolCommons.updateInterestRate()
 
  write state:
@@ -186,7 +186,7 @@
  - Deposits.mult() (scale Fenwick tree with new interest accrued):
  - update scaling array state 
  - increment reserveAuction.totalInterestEarned accumulator
- - Auctions.kickWithDeposit():
+ - KickerActions.lenderKick():
  - _kick():
  - _recordAuction():
  - borrower -> liquidation mapping update
@@ -198,10 +198,6 @@
  - Loans.remove():
  - delete borrower from indices => borrower address mapping
  - remove loan from loans array
- - Deposits.unscaledRemove() (remove amount in Fenwick tree, from index):
- - update values array state
- - decrement lender.lps accumulator
- - decrement bucket.lps accumulator
  - increment poolBalances.t0DebtInAuction and poolBalances.t0Debt accumulators
  - _updateInterestState():
  - PoolCommons.updateInterestRate():
@@ -210,15 +206,14 @@
  - pool inflator and inflatorUpdate state
 
  reverts on:
- - Auctions.kickWithDeposit():
- - auction active AuctionActive()
+ - KickerActions.lenderKick():
+ - bucket price below current pool LUP PriceBelowLUP()
  - borrower collateralized BorrowerOk()
  - insuficient amount InsufficientLiquidity()
 
  emit events:
- - Auctions.kickWithDeposit():
+ - KickerActions.lenderKick():
  - Kick
- - RemoveQuoteToken
  - PoolCommons.updateInterestRate():
  - UpdateInterestRate
 
@@ -235,41 +230,41 @@
 
 ### kickReserveAuction
  external libraries call:
- - Auctions.kickReserveAuction()
+ - KickerActions.kickReserveAuction()
 
  write state:
- - Auctions.kickReserveAuction():
+ - KickerActions.kickReserveAuction():
  - update reserveAuction.unclaimed accumulator
  - update reserveAuction.kicked timestamp state
  - increment latestBurnEpoch counter
  - update reserveAuction.latestBurnEventEpoch and burn event timestamp state
 
  reverts on:
  - 2 weeks not passed ReserveAuctionTooSoon()
- - Auctions.kickReserveAuction():
+ - KickerActions.kickReserveAuction():
  - no reserves to claim NoReserves()
 
  emit events:
- - Auctions.kickReserveAuction():
+ - KickerActions.kickReserveAuction():
  - KickReserveAuction
 
 
 ### takeReserves
  external libraries call:
- - Auctions.takeReserves()
+ - TakerActions.takeReserves()
 
  write state:
- - Auctions.takeReserves():
+ - TakerActions.takeReserves():
  - decrement reserveAuction.unclaimed accumulator
  - increment reserveAuction.totalAjnaBurned accumulator
  - update burn event totalInterest and totalBurned accumulators
 
  reverts on:
- - Auctions.takeReserves():
+ - TakerActions.takeReserves():
  - not kicked or 72 hours didn't pass NoReservesAuction()
 
  emit events:
- - Auctions.takeReserves():
+ - TakerActions.takeReserves():
  - ReserveAuction
 
 ### stampLoan
@@ -387,7 +382,7 @@
  - update scaling array state
  - increment reserveAuction.totalInterestEarned accumulator
  - BorrowerActions.drawDebt():
- - Auctions._settleAuction():
+ - SettlerActions._settleAuction():
  - _removeAuction():
  - decrement kicker locked accumulator, increment kicker claimable accumumlator
  - decrement auctions count accumulator
@@ -417,7 +412,7 @@
 
  emit events:
  - BorrowerActions.drawDebt():
- - Auctions._settleAuction():
+ - SettlerActions._settleAuction():
  - AuctionNFTSettle or AuctionSettle
  - DrawDebt
  - PoolCommons.updateInterestRate():
@@ -436,7 +431,7 @@
  - update scaling array state
  - increment reserveAuction.totalInterestEarned accumulator
  - BorrowerActions.repayDebt():
- - Auctions._settleAuction():
+ - SettlerActions._settleAuction():
  - _removeAuction():
  - decrement kicker locked accumulator, increment kicker claimable accumumlator
  - decrement auctions count accumulator
@@ -466,7 +461,7 @@
 
  emit events:
  - BorrowerActions.repayDebt():
- - Auctions._settleAuction:
+ - SettlerActions._settleAuction:
  - AuctionNFTSettle or AuctionSettle
  - RepayDebt
  - PoolCommons.updateInterestRate():
@@ -475,7 +470,7 @@
 ### settle
  external libraries call:
  - PoolCommons.accrueInterest()
- - Auctions.settlePoolDebt()
+ - SettlerActions.settlePoolDebt()
  - PoolCommons.updateInterestRate()
 
  write state:
@@ -484,14 +479,14 @@
  - Deposits.mult() (scale Fenwick tree with new interest accrued):
  - update scaling array state
  - increment reserveAuction.totalInterestEarned accumulator
- - Auctions.settlePoolDebt():
+ - SettlerActions.settlePoolDebt():
  - Deposits.unscaledRemove() (remove amount in Fenwick tree, from index):
  - update values array state
  - Buckets.addCollateral():
  - increment bucket.collateral and bucket.lps accumulator
  - addLenderLP():
  - increment lender.lps accumulator and lender.depositTime state
- - Auctions._settleAuction():
+ - SettlerActions._settleAuction():
  - _removeAuction():
  - decrement kicker locked accumulator, increment kicker claimable accumumlator
  - decrement auctions count accumulator
@@ -508,14 +503,14 @@
  - pool inflator and inflatorUpdate state
 
  reverts on:
- - Auctions.settlePoolDebt():
+ - SettlerActions.settlePoolDebt():
  - loan not kicked NoAuction()
  - 72 hours didn't pass and auction still has collateral AuctionNotClearable()
 
  emit events:
- - Auctions.settlePoolDebt():
+ - SettlerActions.settlePoolDebt():
  - Settle
- - Auctions._settleAuction():
+ - SettlerActions._settleAuction():
  - AuctionNFTSettle or AuctionSettle
  - BucketBankruptcy
  - PoolCommons.updateInterestRate():
@@ -524,7 +519,7 @@
 ### take
  external libraries call:
  - PoolCommons.accrueInterest()
- - Auctions.take()
+ - TakerActions.take()
  - PoolCommons.updateInterestRate()
 
  write state:
@@ -533,7 +528,7 @@
  - Deposits.mult (scale Fenwick tree with new interest accrued):
  - update scaling array state
  - increment reserveAuction.totalInterestEarned accumulator
- - Auctions.take():
+ - TakerActions.take():
  - _take():
  - _prepareTake():
  - update liquidation.alreadyTaken state
@@ -542,7 +537,7 @@
  - update kicker's locked balance accumulator
  - update auctions.totalBondEscrowed accumulator
  - _takeLoan():
- - Auctions._settleAuction():
+ - SettlerActions._settleAuction():
  - _removeAuction():
  - decrement kicker locked accumulator, increment kicker claimable accumumlator
  - decrement auctions count accumulator
@@ -564,7 +559,7 @@
  - pool inflator and inflatorUpdate state
 
  reverts on:
- - Auctions.take():
+ - TakerActions.take():
  - insufficient collateral InsufficientCollateral()
  - _prepareTake():
  - loan is not in auction NoAuction()
@@ -573,15 +568,15 @@
  - borrower debt less than pool min debt AmountLTMinDebt()
 
  emit events:
- - Auctions.take():
+ - TakerActions.take():
  - Take
  - PoolCommons.updateInterestRate():
  - UpdateInterestRate
 
 ### bucketTake
  external libraries call:
  - PoolCommons.accrueInterest()
- - Auctions.bucketTake()
+ - TakerActions.bucketTake()
  - PoolCommons.updateInterestRate()
 
  write state:
@@ -590,7 +585,7 @@
  - Deposits.mult (scale Fenwick tree with new interest accrued):
  - update scaling array state
  - increment reserveAuction.totalInterestEarned accumulator
- - Auctions.bucketTake():
+ - TakerActions.bucketTake():
  - _takeBucket():
  - _prepareTake():
  - update liquidation.alreadyTaken state
@@ -605,7 +600,7 @@
  - update values array state
  - increment bucket.collateral and bucket.lps accumulator
  - _takeLoan():
- - Auctions._settleAuction():
+ - SettlerActions._settleAuction():
  - _removeAuction():
  - decrement kicker locked accumulator, increment kicker claimable accumumlator
  - decrement auctions count accumulator
@@ -627,7 +622,7 @@
  - pool inflator and inflatorUpdate state
 
  reverts on:
- - Auctions.bucketTake():
+ - TakerActions.bucketTake():
  - insufficient collateral InsufficientCollateral()
  - _prepareTake():
  - loan is not in auction NoAuction()
@@ -636,7 +631,7 @@
  - borrower debt less than pool min debt AmountLTMinDebt()
 
  emit events:
- - Auctions.bucketTake():
+ - TakerActions.bucketTake():
  - _rewardBucketTake():
  - BucketTakeLPAwarded
  - BucketTake

src/base/Pool.sol

@@ -291,7 +291,7 @@ abstract contract Pool is Clone, ReentrancyGuard, Multicall, IPool {
  );
 
  // update in memory pool state struct
- poolState.debt = Maths.wmul(result.t0PoolDebt, poolState.inflator);
+ poolState.debt = result.poolDebt;
  poolState.t0Debt = result.t0PoolDebt;
  poolState.t0DebtInAuction += result.t0KickedDebt;
 
@@ -318,14 +318,14 @@ abstract contract Pool is Clone, ReentrancyGuard, Multicall, IPool {
  * @dev increment `poolBalances.t0DebtInAuction` and `poolBalances.t0Debt` accumulators
  * @dev update `t0Debt2ToCollateral` ratio, debt and collateral post action are considered 0
  */
- function kickWithDeposit(
+ function lenderKick(
  uint256 index_,
  uint256 npLimitIndex_
  ) external override nonReentrant {
  PoolState memory poolState = _accruePoolInterest();
 
  // kick auctions
- KickResult memory result = KickerActions.kickWithDeposit(
+ KickResult memory result = KickerActions.lenderKick(
  auctions,
  deposits,
  buckets,
@@ -336,7 +336,7 @@ abstract contract Pool is Clone, ReentrancyGuard, Multicall, IPool {
  );
 
  // update in memory pool state struct
- poolState.debt = Maths.wmul(result.t0PoolDebt, poolState.inflator);
+ poolState.debt = result.poolDebt;
  poolState.t0Debt = result.t0PoolDebt;
  poolState.t0DebtInAuction += result.t0KickedDebt;
 

src/interfaces/pool/commons/IPoolInternals.sol

@@ -15,9 +15,10 @@ struct KickResult {
  uint256 amountToCoverBond; // [WAD] amount of bond that needs to be covered
  uint256 t0PoolDebt; // [WAD] t0 debt in pool after kick
  uint256 t0KickedDebt; // [WAD] new t0 debt after kick
- uint256 lup; // [WAD] current lup
  uint256 debtPreAction; // [WAD] The amount of borrower t0 debt before kick
  uint256 collateralPreAction; // [WAD] The amount of borrower collateral before kick, same as the one after kick
+ uint256 poolDebt; // [WAD] current debt in pool after kick
+ uint256 lup; // [WAD] current LUP in pool after kick
 }
 
 /// @dev Struct used to hold parameters for `SettlerAction.settlePoolDebt` action.

src/interfaces/pool/commons/IPoolKickerActions.sol

@@ -22,11 +22,11 @@ interface IPoolKickerActions {
  ) external;
 
  /**
- * @notice Called by lenders to liquidate the top loan using their deposits.
+ * @notice Called by lenders to liquidate the top loan.
  * @param index_ The deposit index to use for kicking the top loan.
  * @param npLimitIndex_ Index of the lower bound of `NP` tolerated when kicking the auction.
  */
- function kickWithDeposit(
+ function lenderKick(
  uint256 index_,
  uint256 npLimitIndex_
  ) external;