Merge branch 'development' into feature/website/new-logos

4 files changed, 58 insertions, 6 deletions

diff --git a/contracts/protocol/CHANGELOG.json b/contracts/protocol/CHANGELOG.json
index 5c3798a69..be374d892 100644
--- a/contracts/protocol/CHANGELOG.json
+++ b/contracts/protocol/CHANGELOG.json
@@ -1,5 +1,18 @@
 [
     {
+        "version": "2.2.0",
+        "changes": [
+            {
+                "note": "Added LibAddressArray",
+                "pr": 1383
+            },
+            {
+                "note": "Add validation and comments to MultiAssetProxy",
+                "pr": 1455
+            }
+        ]
+    },
+    {
         "timestamp": 1544741676,
         "version": "2.1.59",
         "changes": [
diff --git a/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol b/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol
index 42231e73b..377325384 100644
--- a/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol
+++ b/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol
@@ -33,6 +33,9 @@ contract MultiAssetProxy is
     function ()
         external
     {
+        // NOTE: The below assembly assumes that clients do some input validation and that the input is properly encoded according to the AbiV2 specification.
+        // It is technically possible for inputs with very large lengths and offsets to cause overflows. However, this would make the calldata prohibitively expensive
+        // and we therefore do not check for overflows in these scenarios.
         assembly {
             // The first 4 bytes of calldata holds the function selector
             let selector := and(calldataload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
@@ -145,7 +148,7 @@ contract MultiAssetProxy is
                 let nestedAssetDataLen := calldataload(sub(nestedAssetDataContentsStart, 32))
 
                 // Revert if number of elements in `amounts` differs from number of elements in `nestedAssetData`
-                if iszero(eq(amountsLen, nestedAssetDataLen)) {
+                if sub(amountsLen, nestedAssetDataLen) {
                     // Revert with `Error("LENGTH_MISMATCH")`
                     mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
                     mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
@@ -181,8 +184,11 @@ contract MultiAssetProxy is
                     let amountsElement := calldataload(add(amountsContentsStart, i))
                     let totalAmount := mul(amountsElement, amount)
 
-                    // Revert if multiplication resulted in an overflow
-                    if iszero(eq(div(totalAmount, amount), amountsElement)) {
+                    // Revert if `amount` != 0 and multiplication resulted in an overflow 
+                    if iszero(or(
+                        iszero(amount),
+                        eq(div(totalAmount, amount), amountsElement)
+                    )) {
                         // Revert with `Error("UINT256_OVERFLOW")`
                         mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
                         mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
@@ -230,7 +236,7 @@ contract MultiAssetProxy is
 
                     // Only load `assetProxy` if `currentAssetProxyId` does not equal `assetProxyId`
                     // We do not need to check if `currentAssetProxyId` is 0 since `assetProxy` is also initialized to 0
-                    if iszero(eq(currentAssetProxyId, assetProxyId)) {
+                    if sub(currentAssetProxyId, assetProxyId) {
                         // Update `assetProxyId`
                         assetProxyId := currentAssetProxyId
                         // To lookup a value in a mapping, we load from the storage location keccak256(k, p),
diff --git a/contracts/protocol/package.json b/contracts/protocol/package.json
index 838189371..d37a0302a 100644
--- a/contracts/protocol/package.json
+++ b/contracts/protocol/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
@@ -44,7 +45,6 @@
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/protocol/README.md",
     "devDependencies": {
         "@0x/abi-gen": "^1.0.19",
-        "@0x/contracts-test-utils": "^1.0.2",
         "@0x/dev-utils": "^1.0.21",
         "@0x/sol-compiler": "^1.1.16",
         "@0x/sol-cov": "^2.1.16",
@@ -75,6 +75,7 @@
         "@0x/contracts-interfaces": "^1.0.2",
         "@0x/contracts-libs": "^1.0.2",
         "@0x/contracts-multisig": "^1.0.2",
+        "@0x/contracts-test-utils": "^1.0.2",
         "@0x/contracts-tokens": "^1.0.2",
         "@0x/contracts-utils": "^1.0.2",
         "@0x/order-utils": "^3.0.7",
diff --git a/contracts/protocol/test/asset_proxy/proxies.ts b/contracts/protocol/test/asset_proxy/proxies.ts
index c4bd95905..89c8b390c 100644
--- a/contracts/protocol/test/asset_proxy/proxies.ts
+++ b/contracts/protocol/test/asset_proxy/proxies.ts
@@ -12,6 +12,7 @@ import {
 import {
     artifacts as tokensArtifacts,
     DummyERC20TokenContract,
+    DummyERC20TokenTransferEventArgs,
     DummyERC721ReceiverContract,
     DummyERC721TokenContract,
     DummyMultipleReturnERC20TokenContract,
@@ -22,6 +23,7 @@ import { assetDataUtils } from '@0x/order-utils';
 import { RevertReason } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import * as chai from 'chai';
+import { LogWithDecodedArgs } from 'ethereum-types';
 import * as _ from 'lodash';
 
 import { ERC20ProxyContract } from '../../generated-wrappers/erc20_proxy';
@@ -738,6 +740,36 @@ describe('Asset Transfer Proxies', () => {
                     erc20Balances[toAddress][erc20TokenA.address].add(totalAmount),
                 );
             });
+            it('should dispatch an ERC20 transfer when input amount is 0', async () => {
+                const inputAmount = constants.ZERO_AMOUNT;
+                const erc20Amount = new BigNumber(10);
+                const erc20AssetData = assetDataUtils.encodeERC20AssetData(erc20TokenA.address);
+                const amounts = [erc20Amount];
+                const nestedAssetData = [erc20AssetData];
+                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
+                    assetData,
+                    fromAddress,
+                    toAddress,
+                    inputAmount,
+                );
+                const erc20Balances = await erc20Wrapper.getBalancesAsync();
+                const logDecoder = new LogDecoder(web3Wrapper, { ...artifacts, ...tokensArtifacts });
+                const tx = await logDecoder.getTxWithDecodedLogsAsync(
+                    await web3Wrapper.sendTransactionAsync({
+                        to: multiAssetProxy.address,
+                        data,
+                        from: authorized,
+                    }),
+                );
+                expect(tx.logs.length).to.be.equal(1);
+                const log = tx.logs[0] as LogWithDecodedArgs<DummyERC20TokenTransferEventArgs>;
+                const transferEventName = 'Transfer';
+                expect(log.event).to.equal(transferEventName);
+                expect(log.args._value).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+                const newBalances = await erc20Wrapper.getBalancesAsync();
+                expect(newBalances).to.deep.equal(erc20Balances);
+            });
             it('should successfully transfer multiple of the same ERC20 token', async () => {
                 const inputAmount = new BigNumber(1);
                 const erc20Amount1 = new BigNumber(10);