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pragma solidity ^0.4.18;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

    /**
    * @dev Multiplies two numbers, throws on overflow.
    */
    function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
        if (a == 0) {
            return 0;
        }
        c = a * b;
        assert(c / a == b);
        return c;
    }

    /**
    * @dev Integer division of two numbers, truncating the quotient.
    */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // assert(b > 0); // Solidity automatically throws when dividing by 0
        // uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return a / b;
    }

    /**
    * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    /**
    * @dev Adds two numbers, throws on overflow.
    */
    function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
        c = a + b;
        assert(c >= a);
        return c;
    }
}

contract ForeignToken {
    function balanceOf(address _owner) constant public returns (uint256);
    function transfer(address _to, uint256 _value) public returns (bool);
}

contract ERC20Basic {
    uint256 public totalSupply;
    function balanceOf(address who) public constant returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
}

contract ERC20 is ERC20Basic {
    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);
}

contract MatoxToken is ERC20 {

    using SafeMath for uint256;
    address owner = msg.sender;

    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;    

    string public constant name = "Matox";
    string public constant symbol = "MAT";
    uint public constant decimals = 8;

    uint256 public totalSupply = 10000000000e8;
    uint256 public totalDistributed = 0;    
    uint256 public constant MIN_CONTRIBUTION = 1 ether /100; // 0.01 Ether
    uint256 public tokensPerEth = 50000e8;

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    event Distr(address indexed to, uint256 amount);
    event DistrFinished();

    event Airdrop(address indexed _owner, uint _amount, uint _balance);

    event TokensPerEthUpdated(uint _tokensPerEth);

    event Burn(address indexed burner, uint256 value);

    bool public distributionFinished = false;

    modifier canDistr() {
        require(!distributionFinished);
        _;
    }

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }


    function MatoxToken () public {
        owner = msg.sender;    
        distr(owner, totalDistributed);
    }

    function transferOwnership(address newOwner) onlyOwner public {
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }


    function finishDistribution() onlyOwner canDistr public returns (bool) {
        distributionFinished = true;
        emit DistrFinished();
        return true;
    }

    function distr(address _to, uint256 _amount) canDistr private returns (bool) {
        totalDistributed = totalDistributed.add(_amount);        
        balances[_to] = balances[_to].add(_amount);
        emit Distr(_to, _amount);
        emit Transfer(address(0), _to, _amount);

        return true;
    }

    function doAirdrop(address _participant, uint _amount) internal {

        require( _amount > 0 );      

        require( totalDistributed < totalSupply );

        balances[_participant] = balances[_participant].add(_amount);
        totalDistributed = totalDistributed.add(_amount);

        if (totalDistributed >= totalSupply) {
            distributionFinished = true;
        }

        // log
        emit Airdrop(_participant, _amount, balances[_participant]);
        emit Transfer(address(0), _participant, _amount);
    }

    function adminClaimAirdrop(address _participant, uint _amount) public onlyOwner {        
        doAirdrop(_participant, _amount);
    }

    function adminClaimAirdropMultiple(address[] _addresses, uint _amount) public onlyOwner {        
        for (uint i = 0; i < _addresses.length; i++) doAirdrop(_addresses[i], _amount);
    }

    function updateTokensPerEth(uint _tokensPerEth) public onlyOwner {        
        tokensPerEth = _tokensPerEth;
        emit TokensPerEthUpdated(_tokensPerEth);
    }

    function () external payable {
        getTokens();
     }

    function getTokens() payable canDistr  public {
        uint256 tokens = 0;

        // minimum contribution
        require( msg.value >= MIN_CONTRIBUTION );

        require( msg.value > 0 );

        // get baseline number of tokens
        tokens = tokensPerEth.mul(msg.value) / 0.01 ether;        
        address investor = msg.sender;

        if (tokens > 0) {
            distr(investor, tokens);
        }

        if (totalDistributed >= totalSupply) {
            distributionFinished = true;
        }
    }

    function balanceOf(address _owner) constant public returns (uint256) {
        return balances[_owner];
    }

    // mitigates the ERC20 short address attack
    modifier onlyPayloadSize(uint size) {
        assert(msg.data.length >= size + 4);
        _;
    }

    function transfer(address _to, uint256 _amount) onlyPayloadSize(2 * 32) public returns (bool success) {

        require(_to != address(0));
        require(_amount <= balances[msg.sender]);

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

    function transferFrom(address _from, address _to, uint256 _amount) onlyPayloadSize(3 * 32) public returns (bool success) {

        require(_to != address(0));
        require(_amount <= balances[_from]);
        require(_amount <= allowed[_from][msg.sender]);

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

    function approve(address _spender, uint256 _value) public returns (bool success) {
        // mitigates the ERC20 spend/approval race condition
        if (_value != 0 && allowed[msg.sender][_spender] != 0) { return false; }
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }

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

    function getTokenBalance(address tokenAddress, address who) constant public returns (uint){
        ForeignToken t = ForeignToken(tokenAddress);
        uint bal = t.balanceOf(who);
        return bal;
    }

    function withdraw() onlyOwner public {
        address myAddress = this;
        uint256 etherBalance = myAddress.balance;
        owner.transfer(etherBalance);
    }

    function burn(uint256 _value) onlyOwner public {
        require(_value <= balances[msg.sender]);
        // no need to require value <= totalSupply, since that would imply the
        // sender's balance is greater than the totalSupply, which *should* be an assertion failure

        address burner = msg.sender;
        balances[burner] = balances[burner].sub(_value);
        totalSupply = totalSupply.sub(_value);
        totalDistributed = totalDistributed.sub(_value);
        emit Burn(burner, _value);
    }

    function withdrawForeignTokens(address _tokenContract) onlyOwner public returns (bool) {
        ForeignToken token = ForeignToken(_tokenContract);
        uint256 amount = token.balanceOf(address(this));
        return token.transfer(owner, amount);
    }
}

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  • 1
    I see, but what is your question? – Nulik Aug 23 '18 at 17:10
  • What do I do, When I try to burn 1 Billion of my token it shows ,Gas Estimation Errored, How do I fix it ?. How Do I burn My token – Isaac Hojo Aug 23 '18 at 17:18
  • You just increase the limit. Remember that geth doesn't correctly estimate gas for contracts that release storage. Check this answer: ethereum.stackexchange.com/questions/56287/… – Nulik Aug 23 '18 at 17:33
  • I increased the limit to 500,000 but still get the same error – Isaac Hojo Aug 23 '18 at 17:41
  • some contracts spend more than block's gas limit, so 500,000 is not really too much – Nulik Aug 23 '18 at 17:50
0

More than a gas issue, it sounds like you are running into the "Always failing clause"

Your Burn function requires that it is only called by the owner, and that the value being burned is less than or equal to the owner's balance. If either of these cases are not satisfied, the transaction will fail regardless of the gas limit.

Moreover, in your constructer, you distribute the totalDistributed amount to the owner, which is 0 by default.

If you haven't credited the owner with at least the amount you are trying to burn, and if the burn tx is signed by a non-owner address, gas estimation will fail.

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