benchmark2/integer overflow/1176.sol

pragma solidity ^0.4.15;


contract Owned {
    address public owner;
    address public newOwner;
    
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    function Owned() public {
        owner = msg.sender;
    }

    function transferOwnership(address _newOwner) onlyOwner public {
        newOwner = _newOwner;
    }

    function acceptOwnership() onlyOwner public {
        OwnershipTransferred(owner, newOwner);
        owner = newOwner;
    }

    event OwnershipTransferred(address indexed _from, address indexed _to);
}

contract ERC20 {
    uint256 public totalSupply;
  
    function balanceOf(address who) public constant returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);
    function allowance(address owner, address spender) public constant returns (uint256);
    function transferFrom(address from, address to, uint256 value) public returns (bool);
    function approve(address spender, uint256 value) public returns (bool);
  
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);
}

contract StandartToken is ERC20 {
    using SafeMath for uint256;

    mapping(address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;
    
    bool public isStarted = false;
    
    modifier isStartedOnly() {
        require(isStarted);
        _;
    }

    function transfer(address _to, uint256 _value) isStartedOnly public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[msg.sender]);

        
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        Transfer(msg.sender, _to, _value);
        return true;
    }

    function balanceOf(address _owner) public constant returns (uint256 balance) {
        return balances[_owner];
    }
  
    function transferFrom(address _from, address _to, uint256 _value) isStartedOnly public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);

        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
        Transfer(_from, _to, _value);
        return true;
    }

    function approve(address _spender, uint256 _value) isStartedOnly public returns (bool) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    function allowance(address _owner, address _spender) public constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

    function increaseApproval (address _spender, uint _addedValue) isStartedOnly public returns (bool success) {
        allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
        Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }

    function decreaseApproval (address _spender, uint _subtractedValue) isStartedOnly public returns (bool success) {
        uint oldValue = allowed[msg.sender][_spender];
        if (_subtractedValue > oldValue) {
            allowed[msg.sender][_spender] = 0;
        } else {
            allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
        }
        Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }
}

library SafeMath {
    function mul(uint256 a, uint256 b) internal constant returns (uint256) {
        uint256 c = a * b;
        assert(a == 0 || c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal constant returns (uint256) {
        
        uint256 c = a / b;
        
        return c;
    }

    function sub(uint256 a, uint256 b) internal constant returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal constant returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}



contract ENDOToken is Owned, StandartToken {
    string public name = "ENDO Token";
    string public symbol = "EDT";
    uint public decimals = 18;

    address public distributionMinter;

    event Mint(address indexed to, uint256 amount);

    modifier canMint() {
        require(!isStarted);
        _;
    }

    modifier onlyDistributionMinter(){
        require(msg.sender == distributionMinter);
        _;
    }

    function () public {
        revert();
    }

    function setDistributionMinter(address _distributionMinter)
        public
        onlyOwner
        canMint
    {
        distributionMinter = _distributionMinter;
    }

    function mint(address _to, uint256 _amount)
        onlyDistributionMinter
        canMint
        public
        returns (bool)
    {
        totalSupply = totalSupply.add(_amount);
        balances[_to] = balances[_to].add(_amount);
        Mint(_to, _amount);
        return true;
    }

    function start()
        onlyDistributionMinter
        canMint
        public
        returns (bool)
    {
        isStarted = true;
        return true;
    }
}