typing: fix/adjust _code.source.getfslineno

[blueyed]

No description provided.

[bluetech]

👍 on the Optional. Curious that it wasn't caught.

Since the caller already needs to handle None, does it make sense to exchange the return '', 1 with return None, -1? Then the type will be simpler. But I didn't check the callers.

[blueyed]

Since the caller already needs to handle None, does it make sense to exchange the return '', 1 with return None, -1? Then the type will be simpler. But I didn't check the callers.

I'm reluctant to messing with code here, but just want to type what is used.

[blueyed]

I think None might only happen in case inspect would return an empty string (a theoretical case I guess).
Also curious why it wasn't caught by mypy, but have not checked.