queryset-refactor: Merged from turnk up to [7135] because I need some stuff.

git-svn-id: http://code.djangoproject.com/svn/django/branches/queryset-refactor@7136 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/datastructures/tests.py

@@ -77,6 +77,8 @@ MultiValueDictKeyError: "Key 'lastname' not found in <MultiValueDict: {'position
 'not one'
 >>> d.keys() == d.copy().keys()
 True
+>>> d2 = d.copy()
+>>> d2['four'] = 'four'
 >>> print repr(d)
 {'one': 'not one', 'two': 'two', 'three': 'three'}
 >>> d.pop('one', 'missing')