Improve clear() method. Keeps key/value refcnts >= 1 until final dict.clear() so that decrefs to zero won't trigger arbitrary code . Also runs a bit faster.
diff --git a/Lib/collections.py b/Lib/collections.py
index 1f1f510..79f6696 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -107,8 +107,14 @@
def clear(self):
'od.clear() -> None. Remove all items from od.'
- for k in dict.keys(self):
- del self[k]
+ try:
+ for node in self.__map.itervalues():
+ del node[:]
+ self.__root[:] = [self.__root, self.__root, None]
+ self.__map.clear()
+ except AttributeError:
+ pass
+ dict.clear(self)
setdefault = MutableMapping.setdefault
update = MutableMapping.update