fix-#1187: count on ListField of EmbeddedDocumentField fails

docs/changelog.rst

@@ -7,6 +7,7 @@ Changes in 0.10.6 - Dev
 - Add support for mocking MongoEngine based on mongomock. #1151
 - Fixed not being able to run tests on Windows. #1153
 - Allow creation of sparse compound indexes. #1114
+- count on ListField of EmbeddedDocumentField fails. #1187
 
 Changes in 0.10.5
 =================

mongoengine/fields.py

@@ -697,7 +697,7 @@ def validate(self, value):
 
     def prepare_query_value(self, op, value):
         if self.field:
-            if op in ('set', 'unset') and (
+            if op in ('set', 'unset', None) and (
                     not isinstance(value, basestring) and
                     not isinstance(value, BaseDocument) and
                     hasattr(value, '__iter__')):

tests/queryset/queryset.py

@@ -3613,6 +3613,15 @@ class MyDoc(Document):
         self.assertEqual(MyDoc.objects.count(), 10)
         self.assertEqual(MyDoc.objects.none().count(), 0)
 
+    def test_count_list_embedded(self):
+        class B(EmbeddedDocument):
+            c = StringField()
+
+        class A(Document):
+            b = ListField(EmbeddedDocumentField(B))
+
+        self.assertEqual(A.objects(b=[{'c': 'c'}]).count(), 0)
+
     def test_call_after_limits_set(self):
         """Ensure that re-filtering after slicing works
         """
@@ -4888,5 +4897,6 @@ class Doc(Document):
 
         self.assertEqual(1, Doc.objects(item__type__="axe").count())
 
+
 if __name__ == '__main__':
     unittest.main()