veToken Finance contest - ElKu's results

https://github.com/code-423n4/2022-05-vetoken/blob/2d7cd1f6780a9bcc8387dea8fecfbd758462c152/contracts/BaseRewardPool.sol#L195

In the above function address _for is not zero-checked.

1. In function https://github.com/code-423n4/2022-05-vetoken/blob/2d7cd1f6780a9bcc8387dea8fecfbd758462c152/contracts/VE3DLocker.sol#L206, we could avoid extra storage reads by declaring the following in memory

rewardData[_rewardsToken].ve3Token, rewardData[_rewardsToken].ve3TokenStaking, rewardData[_rewardsToken].veAssetDeposits. Since the calls are made inside a for loop, this saves around 3100-32*3=282 gas per iteration.

2. Very similar to the above point, in the function, https://github.com/code-423n4/2022-05-vetoken/blob/2d7cd1f6780a9bcc8387dea8fecfbd758462c152/contracts/VE3DRewardPool.sol#L275 , the following state variables can be stored in memory before accessing them. rewardTokenInfo[_rewardToken].veAssetDeposits, rewardTokenInfo[_rewardToken].ve3Token, rewardTokenInfo[_rewardToken].ve3TokenRewards

They are all called inside a for loop, so this will save a lot of gas.

3. The if statement here, https://github.com/code-423n4/2022-05-vetoken/blob/2d7cd1f6780a9bcc8387dea8fecfbd758462c152/contracts/ExtraRewardStashV3.sol#L87 is redundant. You could simply assign tokenCount to i and save 100 gas.

4. There is some redundancy in the claimRewards function. https://github.com/code-423n4/2022-05-vetoken/blob/2d7cd1f6780a9bcc8387dea8fecfbd758462c152/contracts/ExtraRewardStashV1.sol#L77 to line 81 could be rewritten as:

   if (tokenInfo.token == address(0)) {
       setToken();
   } else 
       address tic = tokenInfo.token; 
       address st = staker;
       uint256 before = IERC20(tic).balanceOf(st);
   

Thus replacing the two state variable reads to memory reads. It saves gas and increases code readability.