portal_view_customization bombs on plone 3.1

[wichert]

  Module zope.tales.tales, line 696, in evaluate
   - URL: index
   - Line 30, Column 2
   - Expression: <PathExpr standard:'view/getTemplateViewRegistrations'>
   - Names:
      {'container': <ViewTemplateContainer at /Plone/portal_view_customizations>,
       'context': <ViewTemplateContainer at /Plone/portal_view_customizations>,
       'default': <object object at 0x6f528>,
       'here': <ViewTemplateContainer at /Plone/portal_view_customizations>,
       'loop': {},
       'nothing': None,
       'options': {'args': (<Products.Five.metaclass.SimpleViewClass from /Users/wichert/Development/instances/plone31/src/plone.app.customerize/plone/app/customerize/registrations.pt object at 0x6f9e0f0>,)},
       'repeat': <Products.PageTemplates.Expressions.SafeMapping object at 0x6f9b8f0>,
       'request': <HTTPRequest, URL=http://localhost:8080/Plone/portal_view_customizations/registrations.html>,
       'root': <Application at >,
       'template': <ImplicitAcquirerWrapper object at 0x6b6a030>,
       'traverse_subpath': [],
       'user': <PropertiedUser 'admin'>,
       'view': <Products.Five.metaclass.SimpleViewClass from /Users/wichert/Development/instances/plone31/src/plone.app.customerize/plone/app/customerize/registrations.pt object at 0x6f9e0f0>,
       'views': <zope.app.pagetemplate.viewpagetemplatefile.ViewMapper object at 0x6d42770>}
  Module zope.tales.expressions, line 217, in __call__
  Module Products.PageTemplates.Expressions, line 161, in _eval
  Module Products.PageTemplates.Expressions, line 123, in render
  Module plone.app.customerize.browser, line 25, in getTemplateViewRegistrations
  Module plone.app.customerize.registration, line 78, in templateViewRegistrationGroups
  Module plone.app.customerize.registration, line 63, in templateViewRegistrationInfos
AttributeError: 'unicode' object has no attribute 'file'

[witsch]

(In [19679]) for some registrations the info attribute can contain a string instead of an actual object holding the file name of the zcml; the culprit here seems to be an addview for some demo content from the new kss release (look for AddSimpleContent.html in /portal_view_customizations), but apparently this pattern just hasn't been used before in plone... (fixes #7918)