Sherlock 105.md: ERC721Pool's mergeOrRemoveCollateral allows to remov…

…e collateral while auction is clearable (#571)

- check _revertIfAuctionClearable in mergeOrRemoveCollateral function
- update tests: add _assertMergeRemoveCollateralAuctionNotClearedRevert and assert in ERC721 mergeOrRemove unit tests

src/ERC721Pool.sol

@@ -282,6 +282,8 @@ contract ERC721Pool is FlashloanablePool, IERC721Pool {
  uint256 noOfNFTsToRemove_,
  uint256 toIndex_
  ) external override nonReentrant returns (uint256 collateralMerged_, uint256 bucketLPs_) {
+ _revertIfAuctionClearable(auctions, loans);
+
  PoolState memory poolState = _accruePoolInterest();
  uint256 collateralAmount = Maths.wad(noOfNFTsToRemove_);
 

tests/forge/ERC721Pool/ERC721DSTestPlus.sol

@@ -530,6 +530,17 @@ abstract contract ERC721DSTestPlus is DSTestPlus, IERC721PoolEvents {
  ERC721Pool(address(_pool)).drawDebt(from, amount, indexLimit, emptyArray);
  }
 
+ function _assertMergeRemoveCollateralAuctionNotClearedRevert(
+ address from,
+ uint256 toIndex,
+ uint256 noOfNFTsToRemove,
+ uint256[] memory removeCollateralAtIndex
+ ) internal {
+ changePrank(from);
+ vm.expectRevert(abi.encodeWithSignature('AuctionNotCleared()'));
+ ERC721Pool(address(_pool)).mergeOrRemoveCollateral(removeCollateralAtIndex, noOfNFTsToRemove, toIndex);
+ }
+
  function _assertCannotMergeToHigherPriceRevert(
  address from,
  uint256 toIndex,

tests/forge/ERC721Pool/ERC721PoolLiquidationsSettle.t.sol

@@ -203,6 +203,14 @@ contract ERC721PoolLiquidationsSettleTest is ERC721HelperContract {
  })
  );
 
+ // revert if auction is not settled
+ _assertMergeRemoveCollateralAuctionNotClearedRevert({
+ from: _lender,
+ toIndex: MAX_FENWICK_INDEX,
+ noOfNFTsToRemove: 2,
+ removeCollateralAtIndex: new uint256[](0)
+ });
+
  _settle({
  from: _lender,
  borrower: _borrower2,
@@ -227,6 +235,14 @@ contract ERC721PoolLiquidationsSettleTest is ERC721HelperContract {
  })
  );
 
+ // revert if auction is not settled
+ _assertMergeRemoveCollateralAuctionNotClearedRevert({
+ from: _lender,
+ toIndex: MAX_FENWICK_INDEX,
+ noOfNFTsToRemove: 2,
+ removeCollateralAtIndex: new uint256[](0)
+ });
+
  // settle borrower
  _settle({
  from: _lender,