Fix #866: does not follow

docs/changelog.rst

@@ -5,6 +5,7 @@ Changelog
 
 Changes in 0.9.X - DEV
 ======================
+- `BaseDict` does not follow `setdefault` #866
 - Add support for $type operator # 766
 - Fix tests for pymongo 2.8+ #877
 - No module named 'django.utils.importlib' (Django dev) #872

mongoengine/base/datastructures.py

@@ -75,6 +75,10 @@ class BaseDict(dict):
         self._mark_as_changed()
         return super(BaseDict, self).popitem(*args, **kwargs)
 
+    def setdefault(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).setdefault(*args, **kwargs)
+
     def update(self, *args, **kwargs):
         self._mark_as_changed()
         return super(BaseDict, self).update(*args, **kwargs)

tests/fields/fields.py

@@ -1176,6 +1176,11 @@ class FieldTest(unittest.TestCase):
         post.reload()
         self.assertEqual('updated', post.info['title'])
 
+        post.info.setdefault('authors', [])
+        post.save()
+        post.reload()
+        self.assertEqual([], post.info['authors'])
+
         BlogPost.drop_collection()
 
     def test_dictfield_strict(self):