Yes, that would be intended. At least, that matches the previous behavior. The new code corresponds to
```
if dif.is_nonnegative is not dif.is_negative and dif.is_nonnegative is not None:
```
which, if you compare to the code before the change, does two things:
1) Change `!=` comparison to `is not` comparison, and
2) add a check that we do not return a `None`.