Submitted by jvaqa, also found by 0xRajeev and [s1m0](https://twitter.com/smonica)
RCTreasury.addToWhitelist() will erroneously remove user from whitelist if user is already whitelisted
The comments state that calling addToWhitelist() should add a user to the whitelist.
However, since the implementation simply flips the users whitelist bool, if the user is already on the whitelist, then calling addToWhitelist() will actually remove them from the whitelist.
Since batchAddToWhitelist() will repeatedly call addToWhitelist() with an entire array of users, it is very possible that someone could inadvertently call addToWhitelist twice for a particular user, thereby leaving them off of the whitelist.
If a governor calls addToWhitelist() with the same user twice, the user will not be added to the whitelist, even though the comments state that they should.
Recommend changing addToWhitelist to only ever flip a users bool to true. To clarify the governors intention, create a corresponding removeFromWhitelist and batchRemoveFromWhitelist which flip a users bool to false, so that the governor does not accidentally remove a user when intending to add them.
Also recommend changing isAllowed[_user] = !isAllowed[_user]; TO isAllowed[_user] = true;, and adding this:
Splidge (Reality Cards) acknowledged but disagreed with severity:
Splidge (Reality Cards) confirmed:
dmvt (Judge) lowered severity from 2 to 1:
