[Zope-dev] more persistent mapping misery

[Chris McDonough]

Hi folks,

On the HEAD recently, a bunch of changes were made to the Persistence
package.  Notably, the Persistence.PersistentMapping module was removed
in favor of a Persistence.mapping module.  Unfortunately, there are
instance pickles lying around in any CMF instance created prior to the
changes (DiscussionItem's _container attribute is the one I found) which
explicitly refer to Persistence.PersistentMapping.PersistentMapping. 
This name can no longer be resolved to a class.  This breaks b/w
compatibility.

I "fixed" the issue by adding the following to the Persistence package's
__init__.py:

sys.modules['Persistence.PersistentMapping'] =
sys.modules['Persistence.mapping']

That seems really ugly, though.  Is there a better way to fix it?

- C