Merge pull request #17 from aave/fix/eth-eth-repay-w-collateral

Fix eth->eth repay with collateral

contracts/adapters/BaseUniswapAdapter.sol

@@ -24,6 +24,7 @@ import {IBaseUniswapAdapter} from './interfaces/IBaseUniswapAdapter.sol';
 abstract contract BaseUniswapAdapter is FlashLoanReceiverBase, IBaseUniswapAdapter, Ownable {
   using SafeMath for uint256;
   using PercentageMath for uint256;
+
   using SafeERC20 for IERC20;
 
   // Max slippage percent allowed
@@ -346,6 +347,18 @@ abstract contract BaseUniswapAdapter is FlashLoanReceiverBase, IBaseUniswapAdapt
     // Subtract flash loan fee
     uint256 finalAmountIn = amountIn.sub(amountIn.mul(FLASHLOAN_PREMIUM_TOTAL).div(10000));
 
+    if (reserveIn == reserveOut) {
+      uint256 reserveDecimals = _getDecimals(reserveIn);
+      return
+        AmountCalc(
+          finalAmountIn,
+          finalAmountIn.mul(10**18).div(amountIn),
+          _calcUsdValue(reserveIn, amountIn, reserveDecimals),
+          _calcUsdValue(reserveIn, finalAmountIn, reserveDecimals),
+          [reserveIn]
+        );
+    }
+
     address[] memory simplePath = new address[](2);
     simplePath[0] = reserveIn;
     simplePath[1] = reserveOut;
@@ -420,6 +433,20 @@ abstract contract BaseUniswapAdapter is FlashLoanReceiverBase, IBaseUniswapAdapt
     address reserveOut,
     uint256 amountOut
   ) internal view returns (AmountCalc memory) {
+    if (reserveIn == reserveOut) {
+      // Add flash loan fee
+      uint256 amountIn = amountOut.add(amountOut.mul(FLASHLOAN_PREMIUM_TOTAL).div(10000));
+      uint256 reserveDecimals = _getDecimals(reserveIn);
+      return
+        AmountCalc(
+          amountIn,
+          amountOut.mul(10**18).div(amountIn),
+          _calcUsdValue(reserveIn, amountIn, reserveDecimals),
+          _calcUsdValue(reserveIn, amountOut, reserveDecimals),
+          [reserveIn]
+        );
+    }
+
     (uint256[] memory amounts, address[] memory path) =
       _getAmountsInAndPath(reserveIn, reserveOut, amountOut);
 

contracts/adapters/UniswapLiquiditySwapAdapter.sol

@@ -208,19 +208,22 @@ contract UniswapLiquiditySwapAdapter is BaseUniswapAdapter {
     PermitSignature memory permitSignature,
     bool useEthPath
   ) internal {
-    
     SwapLiquidityLocalVars memory vars;
 
     vars.aToken = _getReserveData(assetFrom).aTokenAddress;
 
     vars.aTokenInitiatorBalance = IERC20(vars.aToken).balanceOf(initiator);
-    vars.amountToSwap =
+    vars.amountToSwap = swapAllBalance && vars.aTokenInitiatorBalance.sub(premium) <= amount
-      swapAllBalance && vars.aTokenInitiatorBalance.sub(premium) <= amount
       ? vars.aTokenInitiatorBalance.sub(premium)
       : amount;
 
-    vars.receivedAmount =
+    vars.receivedAmount = _swapExactTokensForTokens(
-      _swapExactTokensForTokens(assetFrom, assetTo, vars.amountToSwap, minAmountToReceive, useEthPath);
+      assetFrom,
+      assetTo,
+      vars.amountToSwap,
+      minAmountToReceive,
+      useEthPath
+    );
 
     // Deposit new reserve
     IERC20(assetTo).safeApprove(address(LENDING_POOL), 0);

contracts/adapters/UniswapRepayAdapter.sol

@@ -200,7 +200,13 @@ contract UniswapRepayAdapter is BaseUniswapAdapter {
       );
 
       // Swap collateral asset to the debt asset
-      _swapTokensForExactTokens(collateralAsset, debtAsset, amounts[0], neededForFlashLoanDebt, useEthPath);
+      _swapTokensForExactTokens(
+        collateralAsset,
+        debtAsset,
+        amounts[0],
+        neededForFlashLoanDebt,
+        useEthPath
+      );
     } else {
       // Pull aTokens from user
       _pullAToken(