Ensure meta.strict does not bypass constructor check

mongoengine/base/document.py

@@ -70,9 +70,9 @@ class BaseDocument(object):
 
         signals.pre_init.send(self.__class__, document=self, values=values)
 
-        # Check if there are undefined fields supplied, if so raise an
+        # Check if there are undefined fields supplied to the constructor,
-        # Exception.
+        # if so raise an Exception.
-        if not self._dynamic and self._meta.get('strict', True):
+        if not self._dynamic and (self._meta.get('strict', True) or _created):
             for var in values.keys():
                 if var not in self._fields.keys() + ['id', 'pk', '_cls', '_text_score']:
                     msg = (

tests/fields/fields.py

@@ -3171,6 +3171,21 @@ class FieldTest(unittest.TestCase):
 
         self.assertRaises(FieldDoesNotExist, test)
 
+    def test_undefined_field_exception_with_strict(self):
+        """Tests if a `FieldDoesNotExist` exception is raised when trying to
+        instanciate a document with a field that's not defined,
+        even when strict is set to False.
+        """
+
+        class Doc(Document):
+            foo = StringField(db_field='f')
+            meta = {'strict': False}
+
+        def test():
+            Doc(bar='test')
+
+        self.assertRaises(FieldDoesNotExist, test)
+
 
 class EmbeddedDocumentListFieldTestCase(unittest.TestCase):