Merge pull request #583 from Gerrrr/distinct_bug

Fixed bug in distinct method

mongoengine/queryset/base.py

@@ -717,7 +717,10 @@ class BaseQuerySet(object):
             # We may need to cast to the correct type eg. ListField(EmbeddedDocumentField)
             doc_field = getattr(self._document._fields.get(field), "field", None)
             instance = getattr(doc_field, "document_type", False)
-            if instance:
+            EmbeddedDocumentField = _import_class('EmbeddedDocumentField')
+            GenericEmbeddedDocumentField = _import_class('GenericEmbeddedDocumentField')
+            if instance and isinstance(doc_field, (EmbeddedDocumentField,
+                                                   GenericEmbeddedDocumentField)):
                 distinct = [instance(**doc) for doc in distinct]
             return distinct
 

tests/queryset/queryset.py

@@ -2735,6 +2735,27 @@ class QuerySetTest(unittest.TestCase):
 
         self.assertEqual(authors, [mark_twain, john_tolkien])
 
+    def test_distinct_ListField_ReferenceField(self):
+        class Foo(Document):
+            bar_lst = ListField(ReferenceField('Bar'))
+
+        class Bar(Document):
+            text = StringField()
+
+        Bar.drop_collection()
+        Foo.drop_collection()
+
+        bar_1 = Bar(text="hi")
+        bar_1.save()
+
+        bar_2 = Bar(text="bye")
+        bar_2.save()
+
+        foo = Foo(bar=bar_1, bar_lst=[bar_1, bar_2])
+        foo.save()
+
+        self.assertEqual(Foo.objects.distinct("bar_lst"), [bar_1, bar_2])
+
     def test_custom_manager(self):
         """Ensure that custom QuerySetManager instances work as expected.
         """