Record values failed save

test/test_model.py

@@ -284,6 +284,18 @@ def testRollBack(self):
             model.NotExistError, Author.FromPrimary, self.connection, new_author.key
         )
 
+    def testFailedUpdate(self):
+        """Author_two's values should default back to the original record stored
+        values after the update has failed."""
+        Author.Create(self.connection, {"name": "W. Shakespeare"})
+        author_two = Author.Create(self.connection, {"name": "W. Shakespeare"})
+        author_two.update({"ID": 1})
+        try:
+            author_two.Save()
+        except self.connection.IntegrityError:
+            pass
+        self.assertDictEqual(dict(author_two), {"ID": 2, "name": "W. Shakespeare"})
+
 
 class NonStandardTableAndRelations(unittest.TestCase):
     """Verified autoloading works for records with an alternate table name."""

uweb3/model.py

@@ -1213,10 +1213,15 @@ def _SaveSelf(self, cursor):
         """
         self._PreSave(cursor)
         difference = self._Changes()
-        if difference:
-            self._RecordUpdate(cursor)
-            self._record.update(difference)
-        self._PostSave(cursor)
+        try:
+            if difference:
+                self._RecordUpdate(cursor)
+                self._record.update(difference)
+            self._PostSave(cursor)
+        except Exception as exc:
+            # After a failed save rollback the record to the stored database values
+            self.update(self._record)
+            raise exc
 
     # ############################################################################
     # Public methods for creation, deletion and storing Record objects.