> I don't think it was ever a requirement of docstrings that their signature fit on one line or that they render fully in IDLE.

I think this is a requirement of IDLE.

> I still think that the rendering of multi-line signatures should be considered separately.  The discussion and issues are different, and people may have different opinions.

Then what about this issue? Legalize the current invalid behavior in the tests? I think that the tests should check the valid behavior and if tests failed then the behavior should be corrected, not tests should be faked.

> For example, why not be smarter about detecting the end of the signature (e.g. first line not having "->")?

This is a reasonable proposal. Let's discuss it.

The objection is that there are such signatures:

    foo(a, b, c,
        e, f, g) -> some result

> Would you object to creating a new issue?

There is no difference for me what issue it will be, but if it will be a different issue, then I do not see any sense in this issue.