From a1e31c29a6b6810b35e025fc8abbadc6d311d2ae Mon Sep 17 00:00:00 2001
From: Noah Zinsmeister <noahwz@gmail.com>
Date: Mon, 3 Feb 2020 11:08:22 -0500
Subject: [PATCH] THRESHOLD -> MINIMUM_TOTAL_SUPPLY

---
 contracts/UniswapV2ERC20.sol                | 26 +++++++++------------
 contracts/interfaces/IUniswapV2ERC20.sol    |  2 +-
 contracts/interfaces/IUniswapV2Exchange.sol |  1 +
 3 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/contracts/UniswapV2ERC20.sol b/contracts/UniswapV2ERC20.sol
index ca6eb5e..056ff71 100644
--- a/contracts/UniswapV2ERC20.sol
+++ b/contracts/UniswapV2ERC20.sol
@@ -13,7 +13,7 @@ contract UniswapV2ERC20 is IUniswapV2ERC20 {
     mapping(address => uint) public balanceOf;
     mapping(address => mapping(address => uint)) public allowance;
 
-    uint public constant THRESHOLD = 10**6;
+    uint public constant MINIMUM_TOTAL_SUPPLY = 10**6;
     bytes32 public DOMAIN_SEPARATOR;
     // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
     bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
@@ -39,18 +39,18 @@ contract UniswapV2ERC20 is IUniswapV2ERC20 {
     }
 
     function _mint(address to, uint value) internal {
-        totalSupply = totalSupply.add(value);
-        uint balance = balanceOf[to].add(value);
-        require(balance >= THRESHOLD, 'UniswapV2: THRESHOLD');
-        balanceOf[to] = balance;
+        uint _totalSupply = totalSupply.add(value);
+        require(_totalSupply >= MINIMUM_TOTAL_SUPPLY, 'UniswapV2: MINIMUM_TOTAL_SUPPLY');
+        totalSupply = _totalSupply;
+        balanceOf[to] = balanceOf[to].add(value);
         emit Transfer(address(0), to, value);
     }
 
     function _burn(address from, uint value) internal {
-        uint balance = balanceOf[from].sub(value);
-        require(balance == 0 || balance >= THRESHOLD, 'UniswapV2: THRESHOLD');
-        balanceOf[from] = balance;
-        totalSupply = totalSupply.sub(value);
+        uint _totalSupply = totalSupply.sub(value);
+        require(_totalSupply == 0 || _totalSupply >= MINIMUM_TOTAL_SUPPLY, 'UniswapV2: MINIMUM_TOTAL_SUPPLY');
+        balanceOf[from] = balanceOf[from].sub(value);
+        totalSupply = _totalSupply;
         emit Transfer(from, address(0), value);
     }
 
@@ -60,12 +60,8 @@ contract UniswapV2ERC20 is IUniswapV2ERC20 {
     }
 
     function _transfer(address from, address to, uint value) private {
-        uint balanceFrom = balanceOf[from].sub(value);
-        uint balanceTo = balanceOf[to].add(value);
-        require(balanceFrom == 0 || balanceFrom >= THRESHOLD, 'UniswapV2: THRESHOLD');
-        require(balanceTo >= THRESHOLD, 'UniswapV2: THRESHOLD');
-        balanceOf[from] = balanceFrom;
-        balanceOf[to] = balanceTo;
+        balanceOf[from] = balanceOf[from].sub(value);
+        balanceOf[to] = balanceOf[to].add(value);
         emit Transfer(from, to, value);
     }
 
diff --git a/contracts/interfaces/IUniswapV2ERC20.sol b/contracts/interfaces/IUniswapV2ERC20.sol
index 7d4b8ee..1b4e2f5 100644
--- a/contracts/interfaces/IUniswapV2ERC20.sol
+++ b/contracts/interfaces/IUniswapV2ERC20.sol
@@ -15,7 +15,7 @@ interface IUniswapV2ERC20 {
     function transfer(address to, uint value) external returns (bool);
     function transferFrom(address from, address to, uint value) external returns (bool);
 
-    function THRESHOLD() external pure returns (uint);
+    function MINIMUM_TOTAL_SUPPLY() external pure returns (uint);
     function DOMAIN_SEPARATOR() external view returns (bytes32);
     function PERMIT_TYPEHASH() external pure returns (bytes32);
     function nonces(address owner) external view returns (uint);
diff --git a/contracts/interfaces/IUniswapV2Exchange.sol b/contracts/interfaces/IUniswapV2Exchange.sol
index 79dbfa5..95f6efe 100644
--- a/contracts/interfaces/IUniswapV2Exchange.sol
+++ b/contracts/interfaces/IUniswapV2Exchange.sol
@@ -15,6 +15,7 @@ interface IUniswapV2Exchange {
     function transfer(address to, uint value) external returns (bool);
     function transferFrom(address from, address to, uint value) external returns (bool);
 
+    function MINIMUM_TOTAL_SUPPLY() external pure returns (uint);
     function DOMAIN_SEPARATOR() external view returns (bytes32);
     function PERMIT_TYPEHASH() external pure returns (bytes32);
     function nonces(address owner) external view returns (uint);