This issue is already fixed by jeremy at Revision 70815, wherein "The
response from an HTTP request is now an HTTPResponse instance instead of
an addinfourl() wrapper instance."

So the issue won't be present in the py3k code ( confirmed).

However, the test added by Daniel,which tests for urlopen() for a
request which is b"verylong" * 8192 still fails. 

It is not just with iteration; but test_200 will fail too if the request
is a large chunk. This is only in py3k branch, test will pass in the
trunk code. I am investigating further.