> mostly for speed reasons that were valid 20+ years ago. I think it is more likely the same issue Posix had, the official standard came after the implementat

> mostly for speed reasons that were valid 20+ years ago. I think it is more likely the same issue Posix had, the official standard came after the implementations. So it had to unify all existing implementations under the same definition. Which means the standard could not require sane behavior if even a single implementation failed to validate its input or two implementations disagreed on the exact error.