carbon pol eth conversion - minor fix

contracts/pol/CarbonPOL.sol

@@ -191,7 +191,9 @@ contract CarbonPOL is ICarbonPOL, Upgradeable, ReentrancyGuardUpgradeable, Utils
     function enableTradingETH(Price memory price) external onlyAdmin validPrice(price) {
         _tradingStartTimes[NATIVE_TOKEN] = uint32(block.timestamp);
         _initialPrice[NATIVE_TOKEN] = price;
-        _ethSaleAmount.current = _ethSaleAmount.initial;
+        _ethSaleAmount.current = address(this).balance > _ethSaleAmount.initial
+            ? _ethSaleAmount.initial
+            : uint128(address(this).balance);
         emit TradingEnabled(NATIVE_TOKEN, price);
     }
 
@@ -410,7 +412,9 @@ contract CarbonPOL is ICarbonPOL, Upgradeable, ReentrancyGuardUpgradeable, Utils
 
         // check if the new sale amount is below the current available eth sale amount
         if (newEthSaleAmount < _ethSaleAmount.current) {
-            _ethSaleAmount.current = newEthSaleAmount;
+            _ethSaleAmount.current = address(this).balance > newEthSaleAmount
+                ? newEthSaleAmount
+                : uint128(address(this).balance);
         }
 
         emit EthSaleAmountUpdated(prevEthSaleAmount, newEthSaleAmount);

test/forge/CarbonPOL.t.sol

@@ -379,6 +379,18 @@ contract CarbonPOLTest is TestFixture {
         carbonPOL.enableTradingETH(price);
     }
 
+    /// @dev test enabling trading for eth should set the current sale amount properly
+    function testEnablingTradingForETHShouldSetTheCurrentSaleAmountProperly() public {
+        vm.startPrank(admin);
+        // set the initial sale amount to a value higher than the pol balance
+        carbonPOL.setEthSaleAmount(uint128(address(carbonPOL).balance * 2));
+        // enable trading for eth
+        carbonPOL.enableTradingETH(ICarbonPOL.Price({ sourceAmount: 100, targetAmount: 10000 }));
+        // check current eth sale amount is set to the contract balance
+        assertEq(carbonPOL.ethSaleAmount().current, address(carbonPOL).balance);
+        vm.stopPrank();
+    }
+
     /// @dev test should revert when setting invalid price for a token
     function testShouldRevertWhenSettingInvalidPriceForToken(uint256 i) public {
         // pick one of these tokens to test