Fixed #5487 -- Added deepcopying ability to lazy() objects, along with a test to demonstrate why the previous code failed. Debugging and patch from John Buchanan.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6276 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/utils/functional.py

@@ -1,3 +1,5 @@
+import copy
+
 def curry(_curried_func, *args, **kwargs):
     def _curried(*moreargs, **morekwargs):
         return _curried_func(*(args+moreargs), **dict(kwargs, **morekwargs))
@@ -101,6 +103,11 @@ def lazy(func, *resultclasses):
             else:
                 raise AssertionError('__mod__ not supported for non-string types')
 
+        def __deepcopy__(self, memo):
+            result = copy.copy(self)
+            memo[id(self)] = result
+            return result
+
     def __wrapper__(*args, **kw):
         # Creates the proxy object, instead of the actual value.
         return __proxy__(args, kw)