[Zope] Security exception after going from 2.6.2 -> 2.7.3

[Jean Jordaan]

Hi all

I kinda fear that this is a FAQ, but Google hasn't helped. We have
some code that worked fine under Zope 2.6.2, but is raising an
exception now:

Unauthorized: The container has no security assertions. Access to None 
of IISet([-994264300, -570961636, -570961635, -164488020, -25364235]) 
denied.

This is the edited traceback::

     *  Module Products.PageTemplates.ZRPythonExpr, line 47, in __call__
       __traceback_info__: here.reservedcustomernumberrange_listing_items()
     * Module Python expression 
"here.reservedcustomernumberrange_listing_items()", line 1, in <expression>
     [...]
     * Module None, line 13, in reservedcustomernumberrange_listing_items
       <FSPythonScript at 
/creme/reservedcustomernumberrange_listing_items used for 
/creme/Setup/ReservedCustomerNumbers>
       Line 13
     * Module AccessControl.ZopeGuards, line 211, in next
     * Module AccessControl.ZopeGuards, line 224, in guard
     * Module Products.VerboseSecurity.VerboseSecurityPolicy, line 157, 
in validate

The code that raises the exception is::

   rids = context.QueryService(meta_type='ReservedCustomerNumberRange')
   result = [context.Catalog.getobject(rid) for rid in rids] # Exception!

As is apparent from the traceback, QueryService returns an IISet::

   from BTrees.IIBTree import IISet
   [...]
   result = IISet()
   [etc]

Any pointers please?
-- 
Jean Jordaan
http://www.upfrontsystems.co.za