The code is 'totally safe and secure' in a nasty, obfuscated way. It takes too much language / system knowledge to tell that negative numbers are covered. Plus,

The code is 'totally safe and secure' in a nasty, obfuscated way. It takes too much language / system knowledge to tell that negative numbers are covered. Plus, here isn't an extra block whose purpose is confusing that is responsible for negative numbers. Instead the behavior is hidden as part of another block that has a simple face-value interpretation. This is (1) fragile but (2) not self-aware that it's fragile. If you don't refactor to avoid fragility at least leave a comment. Or how about unit tests? If you don't question the motives of the author you should at least question their coding ability.