Dos in `collectPaymentTokens`if token Revert on Zero Value

[hats-bug-reporter[bot]]

Github username: @mgf15 Twitter username: -- Submission hash (on-chain): 0xea0554a86b421deb3891f5368d576522745b01acf5dfdaf6b6c240dd57a8ad1c Severity: medium

Description: Description\ Some tokens (e.g. LEND) revert when transferring a zero value amount. Attack Scenario\ there no check if the paymentToken.balanceOf(address(this)) is zero , if the IERC20 paymentToken = IERC20(_paymentTokens[i]); is token Revert on Zero Value the and paymentToken.balanceOf(address(this)) is zero collectPaymentTokens will be DOSed . Attachments

1. Proof of Concept (PoC) File

   function collectPaymentTokens(address[] calldata _paymentTokens) external onlyOwner nonReentrant {
       address _paymentTokenBeneficiary = paymentTokenBeneficiary;
       if (_paymentTokenBeneficiary == address(0)) {
           revert PaymentTokenNotSupported();
       }
       uint256 len = _paymentTokens.length;
   
       unchecked {
           for (uint256 i; i < len; ++i) {
               //@audit will Dos if token Revert on Zero Value
               IERC20 paymentToken = IERC20(_paymentTokens[i]);
               paymentToken.safeTransfer(_paymentTokenBeneficiary, paymentToken.balanceOf(address(this)));
           }
       }
   }

2. Revised Code File (Optional)

[0xRektora]

The revert is a feature, not a bug. I see nothing wrong with reverting on balance 0 of a token. Protocol just has to not put it in the array param.