Current class fields when unpickling. Fixes #888

Optimize dereferencing map by using sets.

tests/document/instance.py

@@ -10,6 +10,7 @@ import uuid
 
 from datetime import datetime
 from bson import DBRef, ObjectId
+from tests import fixtures
 from tests.fixtures import (PickleEmbedded, PickleTest, PickleSignalsTest,
                             PickleDyanmicEmbedded, PickleDynamicTest)
 
@@ -2085,6 +2086,29 @@ class InstanceTest(unittest.TestCase):
         self.assertEqual(pickle_doc.string, "Two")
         self.assertEqual(pickle_doc.lists, ["1", "2", "3"])
 
+    def test_regular_document_pickle(self):
+
+        pickle_doc = PickleTest(number=1, string="One", lists=['1', '2'])
+        pickled_doc = pickle.dumps(pickle_doc)  # make sure pickling works even before the doc is saved
+        pickle_doc.save()
+
+        pickled_doc = pickle.dumps(pickle_doc)
+
+        # Test that when a document's definition changes the new
+        # definition is used
+        fixtures.PickleTest = fixtures.NewDocumentPickleTest
+
+        resurrected = pickle.loads(pickled_doc)
+        self.assertEqual(resurrected.__class__,
+                         fixtures.NewDocumentPickleTest)
+        self.assertEqual(resurrected._fields_ordered,
+                         fixtures.NewDocumentPickleTest._fields_ordered)
+        self.assertNotEqual(resurrected._fields_ordered,
+                            pickle_doc._fields_ordered)
+
+        # The local PickleTest is still a ref to the original
+        fixtures.PickleTest = PickleTest
+
     def test_dynamic_document_pickle(self):
 
         pickle_doc = PickleDynamicTest(