Two external function calls not working in combination in our smart contract

Question

So I have the following functions

buyTokens

function buyTokens(address beneficiary) public payable {
    require(beneficiary != address(0));
    require(validPurchase());

    uint256 weiAmount = msg.value;

    uint256 tokens = weiAmount.mul(getRate());

    weiRaised = weiRaised.add(weiAmount);

    token.issue(address(vault), tokens);
    vault.deposit.value(msg.value)(beneficiary, tokens);

    emit TokenPurchase(msg.sender, beneficiary, weiAmount, tokens);

    forwardFunds();
}

forwardFunds

function forwardFunds() internal {
    wallet.transfer(msg.value);
}

deposit (in another smart contract)

function deposit(address supporter, uint256 tokensAmount) onlyOwner public payable{

    depositedETH[supporter] = depositedETH[supporter].add(msg.value);
    depositedToken[supporter] = depositedToken[supporter].add(tokensAmount);

    emit Deposit(supporter, msg.value, tokensAmount);
}

So buyTokens won't work unless I comment out EITHER the deposit call or the forwardFunds call. After doing some reading I was thinking that it had something to do with gas?

Furthermore, if I call the deposit function by passing the value as a param rather than receiving through the msg object in the other function (not using .value() methodology) it works fine.

vault.deposit(beneficiary, tokens, msg.value)

Is there an issue with using a .value() call and also forwarding to an internal function that uses .transfer()?

Thanks!

Answer 1

This is forwarding the ether sent to the vault contract

vault.deposit.value(msg.value)(beneficiary, tokens);

And this is forwarding the ether sent to the wallet contract

wallet.transfer(msg.value);

Obviously you cannot forward the same ether to two different contracts.