Add GST support to DFB

contracts/asset-proxy/CHANGELOG.json

@@ -21,6 +21,9 @@
             {
                 "note": "Add `DexForwaderBridge` bridge contract.",
                 "pr": 2525
+            },
+            {
+                "note": "Add Gas Token freeing to `DexForwaderBridge` contract."
             }
         ]
     },

contracts/asset-proxy/contracts/src/bridges/DexForwarderBridge.sol

@@ -23,15 +23,19 @@ import "@0x/contracts-erc20/contracts/src/interfaces/IERC20Token.sol";
 import "@0x/contracts-erc20/contracts/src/LibERC20Token.sol";
 import "@0x/contracts-exchange-libs/contracts/src/IWallet.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibMath.sol";
+import "@0x/contracts-utils/contracts/src/DeploymentConstants.sol";
 import "@0x/contracts-utils/contracts/src/LibBytes.sol";
 import "@0x/contracts-utils/contracts/src/LibSafeMath.sol";
 import "../interfaces/IERC20Bridge.sol";
+import "./MixinGasToken.sol";
 
 
 // solhint-disable space-after-comma, indent
 contract DexForwarderBridge is
     IERC20Bridge,
-    IWallet
+    IWallet,
+    DeploymentConstants,
+    MixinGasToken
 {
     using LibSafeMath for uint256;
 
@@ -68,6 +72,7 @@ contract DexForwarderBridge is
         bytes calldata bridgeData
     )
         external
+        freesGasTokensFromCollector
         returns (bytes4 success)
     {
         TransferFromState memory state;
@@ -84,16 +89,15 @@ contract DexForwarderBridge is
                 break;
             }
 
-            BridgeCall memory call = state.calls[i];
             // Compute token amounts.
             state.callInputTokenAmount = LibSafeMath.min256(
-                call.inputTokenAmount,
+                state.calls[i].inputTokenAmount,
                 state.initialInputTokenBalance.safeSub(state.totalInputTokenSold)
             );
             state.callOutputTokenAmount = LibMath.getPartialAmountFloor(
                 state.callInputTokenAmount,
-                call.inputTokenAmount,
+                state.calls[i].inputTokenAmount,
-                call.outputTokenAmount
+                state.calls[i].outputTokenAmount
             );
 
             // Execute the call in a new context so we can recoup transferred
@@ -101,13 +105,13 @@ contract DexForwarderBridge is
             (bool didSucceed, ) = address(this)
                 .call(abi.encodeWithSelector(
                     this.executeBridgeCall.selector,
-                    call.target,
+                    state.calls[i].target,
                     to,
                     state.inputToken,
                     outputToken,
                     state.callInputTokenAmount,
                     state.callOutputTokenAmount,
-                    call.bridgeData
+                    state.calls[i].bridgeData
                 ));
 
             if (didSucceed) {

contracts/asset-proxy/contracts/test/TestDexForwarderBridge.sol

@@ -156,6 +156,7 @@ contract TestDexForwarderBridge is
     ITestDexForwarderBridge,
     DexForwarderBridge
 {
+
     function createBridge(
         bytes4 returnCode,
         string memory revertError
@@ -217,4 +218,12 @@ contract TestDexForwarderBridge is
     function balanceOf(address token, address owner) public view returns (uint256) {
         return TestDexForwarderBridgeTestToken(token).balanceOf(owner);
     }
+
+    function _getGstAddress()
+        internal
+        view
+        returns (address gst)
+    {
+        return address(0);
+    }
 }

packages/asset-swapper/src/utils/market_operation_utils/orders.ts

@@ -152,10 +152,19 @@ export function createOrdersFromPath(path: Fill[], opts: CreateOrderFromPathOpts
             ++i;
             continue;
         }
+        // Liquidity Provider must be called by ERC20BridgeProxy
+        if (collapsedPath[i].source === ERC20BridgeSource.LiquidityProvider) {
+            orders.push(createBridgeOrder(collapsedPath[i], opts));
+            ++i;
+            continue;
+        }
         // If there are contiguous bridge orders, we can batch them together.
         const contiguousBridgeFills = [collapsedPath[i]];
         for (let j = i + 1; j < collapsedPath.length; ++j) {
-            if (collapsedPath[j].source === ERC20BridgeSource.Native) {
+            if (
+                collapsedPath[j].source === ERC20BridgeSource.Native ||
+                collapsedPath[j].source === ERC20BridgeSource.LiquidityProvider
+            ) {
                 break;
             }
             contiguousBridgeFills.push(collapsedPath[j]);

packages/contract-addresses/CHANGELOG.json

@@ -29,6 +29,12 @@
             {
                 "note": "Redeploy `Forwarder` on all networks",
                 "pr": 2521
+            },
+            {
+                "note": "Redeploy `DexForwarderBridge` on Mainnet with Gas Token freeing"
+            },
+            {
+                "note": "Revert to older Curve Bridge (without Gas Tokens)"
             }
         ]
     },

packages/contract-addresses/addresses.json

@@ -28,9 +28,9 @@
         "godsUnchainedValidator": "0x09a379ef7218bcfd8913faa8b281ebc5a2e0bc04",
         "broker": "0xd4690a51044db77d91d7aa8f7a3a5ad5da331af0",
         "chainlinkStopLimit": "0xeb27220f95f364e1d9531992c48613f231839f53",
-        "curveBridge": "0x1cf6ccc7e15d0d99a9498f37e16ba65b5c54bdd0",
+        "curveBridge": "0x6dc7950423ada9f56fb2c93a23edb787f1e29088",
         "maximumGasPrice": "0xe2bfd35306495d11e3c9db0d8de390cda24563cf",
-        "dexForwarderBridge": "0xa96844087062acf8556ca06a27702c6d19f87e57"
+        "dexForwarderBridge": "0x2b135c732110be20db72e44ab2a4b149fa213599"
     },
     "3": {
         "erc20Proxy": "0xb1408f4c245a23c31b98d2c626777d4c0d766caa",