patches: make Shared.DC.Scripts.Bindings and ZPublisher.BeforeTraverse.MultiHook new-style classes

This backports parts of zope 4 commits [bb7837c66 (Explicitly make all
classes new-style., 2017-09-15)](https://github.com/zopefoundation/Zope/commit/bb7837c66) and [173658008 (Fix unpickling of instances
those base class changed to a new-style class. (#208), 2017-10-24)](https://github.com/zopefoundation/Zope/commit/173658008) for zope2.

This is done for two reasons:
 - so that business template XML are same when exported from zope4
   and from zope2
 - so that a business template created from zope4 can still be
   installed on zope2.

See merge request !1596

product/ERP5Type/ZopePatch.py

@@ -107,6 +107,8 @@ from Products.ERP5Type.patches import WSGITask
 if six.PY2:
   # XXX-zope4py3: urllib2 removed (see future/backports/urllib/request.py)
   from Products.ERP5Type.patches import urllib_opener
+from Products.ERP5Type.patches import SharedDCScriptsBindings
+from Products.ERP5Type.patches import ZPublisherBeforeTraverse
 
 # These symbols are required for backward compatibility
 from Products.ERP5Type.patches.PropertyManager import ERP5PropertyManager

product/ERP5Type/patches/DateTimePatch.py

@@ -278,7 +278,6 @@ def DateTime_parse(self, st, datefmt=getDefaultDateFormat()):
 
 DateTimeKlass._parse = DateTime_parse
 
-
 # DateTime 3 removed exceptions as class attributes (since
 # zopefoundation/DateTime commit 8114618 ), but we have some code expecting
 # these attributes, so undo this patch for convenience.
@@ -286,3 +285,13 @@ DateTimeKlass.DateTimeError = DateTimeError
 DateTimeKlass.SyntaxError = SyntaxError
 DateTimeKlass.DateError = DateError
 DateTimeKlass.TimeError = TimeError
+
+# BBB undo patch from DateTime 2.12 , which patches
+# copy_reg._reconstructor with a function that appears as
+# `DateTime.DateTime._dt_reconstructor` in pickles.
+# See https://github.com/zopefoundation/DateTime/blob/2.12.8/src/DateTime/DateTime.py#L1863-L1874
+# This patch is no longer needed once we are using DateTime >= 3 so
+# it is not needed on python3 (copy_reg does not exist on python3)
+import copy_reg
+copy_reg._reconstructor.__module__ = 'copy_reg'
+copy_reg._reconstructor.__name__ = '_reconstructor'

product/ERP5Type/patches/SharedDCScriptsBindings.py

+import Shared.DC.Scripts.Bindings
+
+# Make Shared.DC.Scripts.Bindings a new style classes already on Zope2, so that
+# we can install business templates exported on Zope4 in Zope2 instances.
+_NameAssignments = Shared.DC.Scripts.Bindings.NameAssignments
+if not isinstance(_NameAssignments, type):
+  class NameAssignments(_NameAssignments, object):
+    def __init__(self, mapping=None):
+      if mapping is None:
+        mapping = {}
+      _NameAssignments.__init__(self, mapping)
+  NameAssignments.__module__ = _NameAssignments.__module__
+
+  Shared.DC.Scripts.Bindings.NameAssignments = NameAssignments

product/ERP5Type/patches/ZPublisherBeforeTraverse.py

+import ZPublisher.BeforeTraverse
+
+# Make ZPublisher.BeforeTraverse.MultiHook a new style classes already on
+# Zope2, so that we can install business templates exported on Zope4 in
+# Zope2 instances.
+_MultiHook = ZPublisher.BeforeTraverse.MultiHook
+if not isinstance(_MultiHook, type):
+  class MultiHook(_MultiHook, object):
+    def __init__(self, hookname='<undefined hookname>', prior=None,
+                 defined_in_class=False):
+      _MultiHook.__init__(self, hookname, prior, defined_in_class)
+    def __repr__(self):
+      # BBB keep the old class repr for testBeforeTraverse
+      return '<ZPublisher.BeforeTraverse.MultiHook instance at 0x%0x (patched in %r)>' % (
+        id(self), __file__)
+  MultiHook.__module__ = _MultiHook.__module__
+
+  ZPublisher.BeforeTraverse.MultiHook = MultiHook