Because we cache so much attribute lookups in local variables,

it is evil to recreate the attributes during _aq_reset.

Scenario:
 * First call to aq_dynamic
 * aq_portal_type = Base.aq_portal_type
    - inner aq_dynamic business
    - causing an aq_reset call
    - Base.aq_portal_type = {}
    - [...]
    - return
* local aq_portal_type is not anymore Base.aq_portal_type

The symptoms are random, hard to reproduce loud KeyError crashes in
  hasattr(aq_portal_type[aq_key], accessor_name, None)
that disappear on the second try.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@39750 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Base.py

@@ -290,8 +290,9 @@ class WorkflowMethod(Method):
       self._invoke_always = {}
 
 def _aq_reset():
-  Base.aq_method_generated = set()
-  Base.aq_portal_type = {}
+  # using clear to prevent changing the reference
+  Base.aq_method_generated.clear()
+  Base.aq_portal_type.clear()
   Base.aq_related_generated = 0
   try:
     from Products.ERP5Form.PreferenceTool import PreferenceTool