Exactly my point. Lots of people think Rust only prevents memory safety bugs, but this is an example of a bug that isn't a memory safety bug but also wouldn't h

Exactly my point. Lots of people think Rust only prevents memory safety bugs, but this is an example of a bug that isn't a memory safety bug but also wouldn't have happened in Rust. They used an int with special meanings for negative/0/positive values. Very common in C, and not at all type safe (all meanings have the same type). In Rust you would use an enum or Result, it would be type safe and the refactoring mistake they made would have been a compile time error.