Somewhere between python 2.7 and now the definition of a method changed causing this helper method in pydoc to break. This was discovered in http://bugs.python.org/issue17464 by r.david.murray when he found it curious that a test I wrote was passing. I had assumed the implemented behavior was correct.

Attached is a patch that ads in an updated version of that test with a fix to the bug. The method updated is only used in that one place as is indicated as private. So it only gets in classes. I went ahead and updated the param to reflect this.