Can you point me to your code and error traceback that was observed and some details about server which gave 301/302 Redirect as what was the hostname and where did it redirect to?

I don't see the code changes that you provided in the patch in the latest versions of urllib, but I am equally surprised if the condition that you said may occur. Because Host will be overridden at some point in time in the Request is made for the new redirected url.

You may want to try with python 2.7 or 2.7.1 too and report if you still face the problem.