Add method for handling imbalance in SAI tokens (#419)

contracts/upgradeable_contracts/erc20_to_native/ForeignBridgeErcToNative.sol

@@ -8,6 +8,7 @@ import "../ChaiConnector.sol";
 
 contract ForeignBridgeErcToNative is BasicForeignBridge, ERC20Bridge, OtherSideBridgeStorage, ChaiConnector {
     bytes32 internal constant MIN_HDTOKEN_BALANCE = 0x48649cf195feb695632309f41e61252b09f537943654bde13eb7bb1bca06964e; // keccak256(abi.encodePacked("minHDTokenBalance"))
+    bytes32 internal constant LOCKED_SAI_FIXED = 0xbeb8b2ece34b32b36c9cc00744143b61b2c23f93adcc3ce78d38937229423051; // keccak256(abi.encodePacked("lockedSaiFixed"))
     bytes4 internal constant SWAP_TOKENS = 0x73d00224; // swapTokens()
 
     function initialize(
@@ -61,6 +62,14 @@ contract ForeignBridgeErcToNative is BasicForeignBridge, ERC20Bridge, OtherSideB
         return 0x18762d46; // bytes4(keccak256(abi.encodePacked("erc-to-native-core")))
     }
 
+    function fixLockedSai(address _receiver) external {
+        require(msg.sender == address(this));
+        require(!boolStorage[LOCKED_SAI_FIXED]);
+        boolStorage[LOCKED_SAI_FIXED] = true;
+        setInvestedAmountInDai(investedAmountInDai() + 49938645266079271041);
+        claimValues(halfDuplexErc20token(), _receiver);
+    }
+
     function claimTokens(address _token, address _to) public {
         require(_token != address(erc20token()));
         // Chai token is not claimable if investing into Chai is enabled

test/erc_to_native/foreign_bridge.test.js

@@ -2201,5 +2201,40 @@ contract('ForeignBridge_ERC20_to_Native', async accounts => {
         }
       })
     })
+
+    describe('fixLockedSai', async () => {
+      it('should fix 49.938645266079271041 locked sai tokens', async () => {
+        const foreignBridgeProxy = await EternalStorageProxy.new().should.be.fulfilled
+        await foreignBridgeProxy.upgradeTo('1', foreignBridge.address).should.be.fulfilled
+        foreignBridge = await ForeignBridge.at(foreignBridgeProxy.address)
+        await foreignBridge.initialize(
+          validatorContract.address,
+          token.address,
+          requireBlockConfirmations,
+          gasPrice,
+          [dailyLimit, maxPerTx, minPerTx],
+          [homeDailyLimit, homeMaxPerTx],
+          owner,
+          decimalShiftZero,
+          otherSideBridge.address
+        ).should.be.fulfilled
+
+        await sai.mint(foreignBridge.address, 100)
+
+        const foreignBridge2 = await ForeignBridgeErcToNativeMock.new()
+        const foreignBridge3 = await ForeignBridgeErcToNativeMock.new()
+
+        const data = foreignBridge.contract.methods.fixLockedSai(accounts[9]).encodeABI()
+
+        await foreignBridgeProxy.upgradeToAndCall('2', foreignBridge2.address, data).should.be.fulfilled
+
+        await sai.mint(foreignBridge.address, 100)
+
+        await foreignBridgeProxy.upgradeToAndCall('3', foreignBridge3.address, data).should.be.rejected
+
+        expect(await sai.balanceOf(accounts[9])).to.be.bignumber.equal('100')
+        expect(await foreignBridge.investedAmountInDai()).to.be.bignumber.equal('49938645266079271041')
+      })
+    })
   })
 })

upgrade/.env.example

@@ -1,6 +1,6 @@
 FOREIGN_RPC_URL=https://mainnet.infura.io/v3/API_KEY
 FOREIGN_PRIVKEY=0x...
-FOREING_BRIDGE_ADDRESS=0x4aa42145Aa6Ebf72e164C9bBC74fbD3788045016
+FOREIGN_BRIDGE_ADDRESS=0x4aa42145Aa6Ebf72e164C9bBC74fbD3788045016
 FOREIGN_START_BLOCK=9122083
 FOREIGN_GAS_PRICE=1000000000
 
@@ -8,3 +8,4 @@ FOREIGN_GAS_PRICE=1000000000
 ROLE=confirm
 
 NEW_IMPLEMENTATION_ETH_BRIDGE=
+SAI_TOKENS_RECEIVER=

upgrade/src/upgradeBridgeOnForeign.js

@@ -2,17 +2,19 @@ require('dotenv').config()
 const Web3 = require('web3')
 const multiSigWalletAbi = require('../abi/multiSigwallet')
 const proxyAbi = require('../../build/contracts/EternalStorageProxy').abi
+const bridgeAbi = require('../../build/contracts/ForeignBridgeErcToNative').abi
 const callMultiSigWallet = require('./utils/callMultiSigWallet')
 const validatorState = require('./utils/validatorState')
 
 const {
   FOREIGN_PRIVKEY,
   FOREIGN_RPC_URL,
-  FOREING_BRIDGE_ADDRESS,
+  FOREIGN_BRIDGE_ADDRESS,
   ROLE,
   FOREIGN_START_BLOCK,
   FOREIGN_GAS_PRICE,
-  NEW_IMPLEMENTATION_ETH_BRIDGE
+  NEW_IMPLEMENTATION_ETH_BRIDGE,
+  SAI_TOKENS_RECEIVER
 } = process.env
 
 const web3 = new Web3(new Web3.providers.HttpProvider(FOREIGN_RPC_URL))
@@ -20,18 +22,21 @@ const { address } = web3.eth.accounts.wallet.add(FOREIGN_PRIVKEY)
 
 const upgradeBridgeOnForeign = async () => {
   try {
-    const proxy = new web3.eth.Contract(proxyAbi, FOREING_BRIDGE_ADDRESS)
+    const proxy = new web3.eth.Contract(proxyAbi, FOREIGN_BRIDGE_ADDRESS)
+    const foreignBridge = new web3.eth.Contract(bridgeAbi, FOREIGN_BRIDGE_ADDRESS)
     const ownerAddress = await proxy.methods.upgradeabilityOwner().call()
     const multiSigWallet = new web3.eth.Contract(multiSigWalletAbi, ownerAddress)
 
     await validatorState(web3, address, multiSigWallet)
 
-    const data = proxy.methods.upgradeTo('5', NEW_IMPLEMENTATION_ETH_BRIDGE).encodeABI()
+    const fixData = foreignBridge.methods.fixLockedSai(SAI_TOKENS_RECEIVER).encodeABI()
+
+    const data = proxy.methods.upgradeToAndCall('6', NEW_IMPLEMENTATION_ETH_BRIDGE, fixData).encodeABI()
 
     await callMultiSigWallet({
       role: ROLE,
       contract: multiSigWallet,
-      destination: FOREING_BRIDGE_ADDRESS,
+      destination: FOREIGN_BRIDGE_ADDRESS,
       fromBlock: FOREIGN_START_BLOCK,
       gasPrice: FOREIGN_GAS_PRICE,
       address,

upgrade/src/utils/callMultiSigWallet.js

@@ -51,7 +51,7 @@ const callMultiSigWallet = async ({ role, contract, destination, fromBlock, gasP
     const gas = await contract.methods.submitTransaction(destination, 0, data).estimateGas({ from: address })
     const receipt = await contract.methods
       .submitTransaction(destination, 0, data)
-      .send({ from: address, gas, gasPrice })
+      .send({ from: address, gas: addExtraGas(gas), gasPrice })
     console.log(`Submission status: ${receipt.status} - Tx Hash: ${receipt.transactionHash}`)
   } else {
     await confirmTransaction({