In a comment on issue 17482, Mike Bayer pointed out a backwards incompatibility resulting from changing inspect.getfullargspec (etc) to rely on inspect.signature: they now follow __wrapped__ chains, where previously they ignored them.

This means that instead of reporting the exact signature of the *wrapper*, they now report the signature of the wrapped function instead.

Since switching these functions from ignoring __wrapped__ to following it is an unintended backwards incompatible change, I'll tweak the code to bypass the unravelling of wrapper chains in the getfullargspec case.