Merge pull request #1784 from werat/fix_override_comment

Restore comment from cached value after queryset copy

mongoengine/queryset/base.py

@@ -1579,6 +1579,9 @@ class BaseQuerySet(object):
         if self._batch_size is not None:
             self._cursor_obj.batch_size(self._batch_size)
 
+        if self._comment is not None:
+            self._cursor_obj.comment(self._comment)
+
         return self._cursor_obj
 
     def __deepcopy__(self, memo):

tests/queryset/queryset.py

@@ -2383,12 +2383,17 @@ class QuerySetTest(unittest.TestCase):
             age = IntField()
 
         with db_ops_tracker() as q:
-            adult = (User.objects.filter(age__gte=18)
+            adult1 = (User.objects.filter(age__gte=18)
                 .comment('looking for an adult')
                 .first())
+
+            adult2 = (User.objects.comment('looking for an adult')
+                .filter(age__gte=18)
+                .first())
+
             ops = q.get_ops()
-            self.assertEqual(len(ops), 1)
-            op = ops[0]
+            self.assertEqual(len(ops), 2)
+            for op in ops:
                 self.assertEqual(op['query']['$query'], {'age': {'$gte': 18}})
                 self.assertEqual(op['query']['$comment'], 'looking for an adult')