String.is_null_terminated assumes _size < _alloc

[Perelandric]

The current implementation of String.is_null_terminated is:

(_alloc > 0) and (_ptr._apply(_size) == 0)

This would seem to point into arbitrary memory when _alloc and _size are the same (in other words, when the String is not null terminated).

let s = String.from_iso_array(recover ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'] end)

env.out.print("is null terminated? (should be false!) " + s.is_null_terminated().string())

is null terminated? (should be false!) true