Pickler.save(): Fix for SF bug #494904: Cannot pickle a class with a

metaclass, reported by Dan Parisien.

Objects that are instances of custom metaclasses, i.e. whose class is
a subclass of 'type', should be pickled the same as new-style classes
(objects whose class is 'type').  This can't be done through a
dispatch table entry, and the __reduce__ trick doesn't work for these,
since it finds the unbound __reduce__ for instances of the class
(inherited from 'object').  So check explicitly using issubclass().

Author: gvanrossum

Lib/pickle.py

@@ -163,6 +163,10 @@ def save(self, object, pers_save = 0):
         try:
             f = self.dispatch[t]
         except KeyError:
+            if issubclass(t, TypeType):
+                self.save_global(object)
+                return
+
             pid = self.inst_persistent_id(object)
             if pid is not None:
                 self.save_pers(pid)