Going back to my earlier point, its success relies on people not seeing it. So I would think its ability to pass a code review would ultimately depend on how many other lines of code it has to hide amongst. If you are reviewing a huge diff and this is hiding somewhere, then OK, maybe I buy it, but it's pretty transparently wrong.

Another test it fails: even if it were == as they are trying to make people think, why would this return EINVAL only if the user is root? There aren't a lot of real world examples where you would want that. It pops out right away as a bogus check that makes no sense, and surprise surprise, it also sets the uid to 0, my guess is in a place where it makes no sense to even look at uid, and very superficially hiding as a "rookie mistake"...