fix: potential second minter blocks burnLockedUSDC (#93)

# 🤖 Linear

Closes OPT-XXX

src/contracts/L1OpUSDCBridgeAdapter.sol

@@ -114,7 +114,15 @@ contract L1OpUSDCBridgeAdapter is IL1OpUSDCBridgeAdapter, OpUSDCBridgeAdapter {
 
  // Burn the USDC tokens
  if (burnAmount != 0) {
- IUSDC(USDC).burn(burnAmount);
+ // NOTE: This is a very edge case and will only happen if the chain operator adds a second minter on L2
+ // So now this adapter doesnt have the full backing supply locked in this contract
+ // Incase the bridged usdc token has other minters and the supply sent is greater then what we have
+ // We need to burn the full amount stored in this contract
+ // This could also cause in-flight messages to fail because of the multiple supply sources
+ uint256 _balanceOf = IUSDC(USDC).balanceOf(address(this));
+ uint256 _burnAmount = burnAmount > _balanceOf ? _balanceOf : burnAmount;
+
+ IUSDC(USDC).burn(_burnAmount);
 
  // Set the burn amount to 0
  burnAmount = 0;

src/interfaces/IL1OpUSDCFactory.sol

@@ -57,7 +57,7 @@ interface IL1OpUSDCFactory {
  function deploy(
  address _l1Messenger,
  address _l1AdapterOwner,
- L2Deployments memory _l2Deployments
+ L2Deployments calldata _l2Deployments
  ) external returns (address _l1Adapter, address _l2Factory, address _l2Adapter);
 
  /*///////////////////////////////////////////////////////////////

test/unit/L1OpUSDCBridgeAdapter.t.sol

@@ -397,6 +397,7 @@ contract L1OpUSDCBridgeAdapter_Unit_BurnLockedUSDC is Base {
  vm.assume(_burnAmount > 0);
 
  _mockAndExpect(_usdc, abi.encodeWithSignature('burn(uint256)', _burnAmount), abi.encode(true));
+ _mockAndExpect(_usdc, abi.encodeWithSignature('balanceOf(address)', address(adapter)), abi.encode(_burnAmount));
 
  adapter.forTest_setBurnAmount(_burnAmount);
 
@@ -416,6 +417,30 @@ contract L1OpUSDCBridgeAdapter_Unit_BurnLockedUSDC is Base {
  vm.mockCall(
  _usdc, abi.encodeWithSignature('burn(address,uint256)', address(adapter), _burnAmount), abi.encode(true)
  );
+ vm.mockCall(_usdc, abi.encodeWithSignature('balanceOf(address)', address(adapter)), abi.encode(_burnAmount));
+
+ adapter.forTest_setBurnAmount(_burnAmount);
+
+ // Execute
+ vm.prank(_circle);
+ adapter.burnLockedUSDC();
+
+ assertEq(adapter.burnAmount(), 0, 'Burn amount should be set to 0');
+ assertEq(adapter.burnCaller(), address(0), 'Circle should be set to 0');
+ }
+
+ /**
+ * @notice Check that balance of gets used if burn amount is greater then the balance
+ */
+ function test_balanceOfUsedIfBurnAmountGt(uint256 _burnAmount, uint256 _balanceOf, address _circle) external {
+ vm.assume(_burnAmount > 0);
+ vm.assume(_burnAmount > _balanceOf);
+ adapter.forTest_setBurnCaller(_circle);
+ adapter.forTest_setMessengerStatus(IL1OpUSDCBridgeAdapter.Status.Deprecated);
+
+ // solhint-disable-next-line max-line-length
+ vm.mockCall(_usdc, abi.encodeWithSignature('burn(address,uint256)', address(adapter), _balanceOf), abi.encode(true));
+ vm.mockCall(_usdc, abi.encodeWithSignature('balanceOf(address)', address(adapter)), abi.encode(_balanceOf));
 
  adapter.forTest_setBurnAmount(_burnAmount);
 
@@ -436,6 +461,7 @@ contract L1OpUSDCBridgeAdapter_Unit_BurnLockedUSDC is Base {
  adapter.forTest_setMessengerStatus(IL1OpUSDCBridgeAdapter.Status.Deprecated);
 
  vm.mockCall(_usdc, abi.encodeWithSignature('burn(address)', address(adapter)), abi.encode(true));
+ vm.mockCall(_usdc, abi.encodeWithSignature('balanceOf(address)', address(adapter)), abi.encode(_burnAmount));
 
  adapter.forTest_setBurnAmount(_burnAmount);