Updated with_id to raise Error if used with a filter.

Closes #365

docs/changelog.rst

@@ -5,6 +5,7 @@ Changelog
 Changes in dev
 ==============
 
+- Added InvalidQueryError when calling with_id with a filter
 - Added support for DBRefs in distinct()
 - Fixed issue saving False booleans
 - Fixed issue with dynamic documents deltas

docs/upgrade.rst

@@ -13,6 +13,7 @@ an InvalidDocument error as they aren't currently supported.
 
 Document._get_subclasses - Is no longer used and the class method has been removed.
 
+Document.objects.with_id - now raises an InvalidQueryError if used with a filter.
 
 0.4 to 0.5
 ===========

mongoengine/queryset.py

@@ -858,10 +858,16 @@ class QuerySet(object):
         return return_one and results[0] or results
 
     def with_id(self, object_id):
-        """Retrieve the object matching the id provided.
+        """Retrieve the object matching the id provided.  Uses `object_id` only
+        and raises InvalidQueryError if a filter has been applied.
 
         :param object_id: the value for the id of the document to look up
+
+        .. versionchanged:: 0.6 Raises InvalidQueryError if filter has been set
         """
+        if not self._query_obj.empty:
+            raise InvalidQueryError("Cannot use a filter whilst using `with_id`")
+
         return self._document.objects(pk=object_id).first()
 
     def in_bulk(self, object_ids):

tests/queryset.py

@@ -154,6 +154,8 @@ class QuerySetTest(unittest.TestCase):
         person = self.Person.objects.with_id(person1.id)
         self.assertEqual(person.name, "User A")
 
+        self.assertRaises(InvalidQueryError, self.Person.objects(name="User A").with_id, person1.id)
+
     def test_find_only_one(self):
         """Ensure that a query using ``get`` returns at most one result.
         """