allowance is not being updated when 2**160-1 is approved
codeislight1 opened this issue · comments
i was wondering in _transfer whether the bypass of updating the allowed.amount when approved amount is 2**160-1 is intended to save on gas, as i have tried to test in 2 cases, for any value under the max, it did deduct from the allowance accordingly. and also I was looking into the test cases and there is a lack of checking for allowance when permit2.transferFrom takes place.
Hey!
bypass of updating the allowed.amount when approved amount is 2**160-1 is intended to save on gas
Yeah, this is a gas optimization (also used in many standard ERC20 tokens) where if the approval is max, we save an sstore on transfer by simply keeping it at max.
I was looking into the test cases and there is a lack of checking for allowance
ah, if we're missing test cases we'd love a PR adding extra coverage!
ohh cool, i ll try to add test cases for them, thank you!