From 7d59faa65069f11bf873215d531637fa0a732232 Mon Sep 17 00:00:00 2001
From: Amir Bandeali <abandeali1@gmail.com>
Date: Fri, 1 Dec 2017 16:47:38 -0800
Subject: Add updated ERC20 implementation, update WETH

---
 packages/contracts/contracts/base/ERC20Token.sol   | 50 +++++++++++++++++++
 .../contracts/contracts/deprecated/EtherToken.sol  | 56 ++++++++++++++++++++++
 packages/contracts/contracts/tokens/EtherToken.sol |  6 ++-
 3 files changed, 110 insertions(+), 2 deletions(-)
 create mode 100644 packages/contracts/contracts/base/ERC20Token.sol
 create mode 100644 packages/contracts/contracts/deprecated/EtherToken.sol

diff --git a/packages/contracts/contracts/base/ERC20Token.sol b/packages/contracts/contracts/base/ERC20Token.sol
new file mode 100644
index 000000000..765cd7274
--- /dev/null
+++ b/packages/contracts/contracts/base/ERC20Token.sol
@@ -0,0 +1,50 @@
+pragma solidity 0.4.11;
+
+import "./Token.sol";
+
+contract ERC20Token is Token {
+
+    uint constant MAX_UINT = 2**256 - 1;
+
+    function transfer(address _to, uint _value) returns (bool) {
+        require(balances[msg.sender] >= _value && balances[_to] + _value >= balances[_to]); 
+        balances[msg.sender] -= _value;
+        balances[_to] += _value;
+        Transfer(msg.sender, _to, _value);
+        return true;
+    }
+
+    /// @dev ERC20 transferFrom, modified such that an allowance of MAX_UINT represents an unlimited allowance. See https://github.com/ethereum/EIPs/issues/717
+    /// @param _from Address to transfer from.
+    /// @param _to Address to transfer to.
+    /// @param _value Amount to transfer.
+    /// @return Success of transfer.
+    function transferFrom(address _from, address _to, uint _value) returns (bool) {
+        require(balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value >= balances[_to]); 
+        balances[_to] += _value;
+        balances[_from] -= _value;
+        if (allowance < MAX_UINT) {
+            allowed[_from][msg.sender] -= _value;
+        }
+        Transfer(_from, _to, _value);
+        return true;
+    }
+
+    function balanceOf(address _owner) constant returns (uint) {
+        return balances[_owner];
+    }
+
+    function approve(address _spender, uint _value) returns (bool) {
+        allowed[msg.sender][_spender] = _value;
+        Approval(msg.sender, _spender, _value);
+        return true;
+    }
+
+    function allowance(address _owner, address _spender) constant returns (uint) {
+        return allowed[_owner][_spender];
+    }
+
+    mapping (address => uint) balances;
+    mapping (address => mapping (address => uint)) allowed;
+    uint public totalSupply;
+}
\ No newline at end of file
diff --git a/packages/contracts/contracts/deprecated/EtherToken.sol b/packages/contracts/contracts/deprecated/EtherToken.sol
new file mode 100644
index 000000000..68148e095
--- /dev/null
+++ b/packages/contracts/contracts/deprecated/EtherToken.sol
@@ -0,0 +1,56 @@
+/*
+
+  Copyright 2017 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.11;
+
+import "./UnlimitedAllowanceToken.sol";
+import "./../base/SafeMath.sol";
+
+contract EtherToken is UnlimitedAllowanceToken, SafeMath {
+
+    string constant public name = "Ether Token";
+    string constant public symbol = "WETH";
+    uint8 constant public decimals = 18;
+
+    /// @dev Fallback to calling deposit when ether is sent directly to contract.
+    function()
+        public
+        payable
+    {
+        deposit();
+    }
+
+    /// @dev Buys tokens with Ether, exchanging them 1:1.
+    function deposit()
+        public
+        payable
+    {
+        balances[msg.sender] = safeAdd(balances[msg.sender], msg.value);
+        totalSupply = safeAdd(totalSupply, msg.value);
+    }
+
+    /// @dev Sells tokens in exchange for Ether, exchanging them 1:1.
+    /// @param amount Number of tokens to sell.
+    function withdraw(uint amount)
+        public
+    {
+        balances[msg.sender] = safeSub(balances[msg.sender], amount);
+        totalSupply = safeSub(totalSupply, amount);
+        require(msg.sender.send(amount));
+    }
+}
diff --git a/packages/contracts/contracts/tokens/EtherToken.sol b/packages/contracts/contracts/tokens/EtherToken.sol
index 68148e095..5c0f0e536 100644
--- a/packages/contracts/contracts/tokens/EtherToken.sol
+++ b/packages/contracts/contracts/tokens/EtherToken.sol
@@ -18,10 +18,10 @@
 
 pragma solidity 0.4.11;
 
-import "./UnlimitedAllowanceToken.sol";
+import "./ERC20Token.sol";
 import "./../base/SafeMath.sol";
 
-contract EtherToken is UnlimitedAllowanceToken, SafeMath {
+contract EtherToken is ERC20Token, SafeMath {
 
     string constant public name = "Ether Token";
     string constant public symbol = "WETH";
@@ -42,6 +42,7 @@ contract EtherToken is UnlimitedAllowanceToken, SafeMath {
     {
         balances[msg.sender] = safeAdd(balances[msg.sender], msg.value);
         totalSupply = safeAdd(totalSupply, msg.value);
+        Transfer(address(0), msg.sender, msg.value);
     }
 
     /// @dev Sells tokens in exchange for Ether, exchanging them 1:1.
@@ -52,5 +53,6 @@ contract EtherToken is UnlimitedAllowanceToken, SafeMath {
         balances[msg.sender] = safeSub(balances[msg.sender], amount);
         totalSupply = safeSub(totalSupply, amount);
         require(msg.sender.send(amount));
+        Tranfer(msg.sender, address(0), msg.value);
     }
 }
-- 
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