added a test

djangorestframework/content.py

@@ -40,7 +40,7 @@ class OverloadedContentMixin(ContentMixin):
         """If the request contains content, returns a tuple of (content_type, content) otherwise returns None.
         Note that content_type may be None if it is unset."""
         if not request.META.get('CONTENT_LENGTH', None) and not request.META.get('TRANSFER_ENCODING', None):
-            return None # TODO : Breaks, because determine_content should return a tuple.
+            return None
         content_type = request.META.get('CONTENT_TYPE', None)
 
         if (request.method == 'POST' and self.CONTENT_PARAM and

djangorestframework/tests/content.py

@@ -111,6 +111,7 @@ class TestContentMixins(TestCase):
                      OverloadedContentMixin.CONTENTTYPE_PARAM: content_type}
         request = self.req.post('/', form_data)
         self.assertEqual(OverloadedContentMixin().determine_content(request), (content_type, content))
+        self.assertEqual(request.META['CONTENT_TYPE'], content_type)
  
     def test_overloaded_behaviour_allows_content_tunnelling_content_type_not_set(self):
         """Ensure determine_content(request) returns (None, content) for overloaded POST request with content type not set"""