Fixing bug setting a value that equates to false

mongoengine/base.py

@@ -762,7 +762,7 @@ class BaseDocument(object):
             if value:
                 continue
 
-            # If we've set a value that ain't the default value unset it.
+            # If we've set a value that ain't the default value dont unset it.
             default = None
 
             if path in self._fields:
@@ -789,8 +789,8 @@ class BaseDocument(object):
             if default is not None:
                 if callable(default):
                     default = default()
-                if default != value:
-                    continue
+            if default != value:
+                continue
 
             del(set_data[path])
             unset_data[path] = 1

tests/document.py

@@ -1048,6 +1048,26 @@ class DocumentTest(unittest.TestCase):
         except ValidationError:
             self.fail()
 
+    def test_save_to_a_value_that_equates_to_false(self):
+
+        class Thing(EmbeddedDocument):
+            count = IntField()
+
+        class User(Document):
+            thing = EmbeddedDocumentField(Thing)
+
+        User.drop_collection()
+
+        user = User(thing=Thing(count=1))
+        user.save()
+        user.reload()
+
+        user.thing.count = 0
+        user.save()
+
+        user.reload()
+        self.assertEquals(user.thing.count, 0)
+
     def test_save_max_recursion_not_hit(self):
 
         class Person(Document):