HistoryArrayList checks internal list as a list or dict to clear it

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/sqlalchemy/util.py b/lib/sqlalchemy/util.py
index d60166a0c..2b522d571 100644
--- a/lib/sqlalchemy/util.py
+++ b/lib/sqlalchemy/util.py
@@ -365,14 +365,19 @@ class HistoryArraySet(UserList.UserList):
         for key, status in self.records.iteritems():
             if status is False or status is None:
                 list.append(key)
-        self.data[:] = []
+        self._clear_data()
         self.records = {}
         for l in list:
             self.append_nohistory(l)
     def clear(self):
         """clears the list and removes all history."""
-        self.data[:] = []
+        self._clear_data()
         self.records = {}
+    def _clear_data(self):
+        if isinstance(self.data, dict):
+            self.data.clear()
+        else:
+            self.data[:] = []
     def added_items(self):
         """returns a list of items that have been added since the last "committed" state."""
         return [key for key in self.data if self.records[key] is True]