ERP5Type: allow pickling temp objects

What should not be allowed is to store persistent objects in ZODB, but pickling
them should be OK. This is necessary if we want to store them in memcached.

This also modifies loadTempPortalTypeClass which was returning a class with a
different name than requested, by prepending "Temporary ". This prevented
pickling, because pickle checks that the class is can be imported under its
same name. This was problematic because before this change, we had such a behavior:

    (Pdb) tmp = self.portal.person_module.newContent(portal_type='Person', temp_object=True)
    (Pdb) tmp.__class__
    <class 'erp5.temp_portal_type.Temporary Person'>
    (Pdb) import erp5.temp_portal_type
    (Pdb) getattr(erp5.temp_portal_type, 'Temporary Person')
    <class 'erp5.temp_portal_type.Temporary Temporary Person'>

My understanding is that this prefix in the class name was not useful, that
class lives in another module than the "real" Person class.

product/ERP5Type/dynamic/portal_type_class.py

@@ -383,9 +383,8 @@ def loadTempPortalTypeClass(portal_type_name):
   """
   import erp5.portal_type
   klass = getattr(erp5.portal_type, portal_type_name)
+  return type(portal_type_name, (TemporaryDocumentMixin, klass), {})
 
-  return type("Temporary " + portal_type_name,
-              (TemporaryDocumentMixin, klass), {})
 
 last_sync = -1
 _bootstrapped = set()

product/ERP5Type/mixin/temporary.py

@@ -35,6 +35,7 @@ from Acquisition import aq_base
 from Products.ERP5Type.Accessor.Constant import PropertyGetter as \
   PropertyConstantGetter
 
+
 class TemporaryDocumentMixin(object):
   """
   Setters and attributes that are attached to temporary documents.
@@ -44,8 +45,10 @@ class TemporaryDocumentMixin(object):
   __roles__ = None
 
   def __getstate__(self):
-    # disallow persistent storage
-    raise PicklingError("Temporary objects can't be pickled")
+    if getattr(self, '_p_jar', None) is not None:
+      # disallow persistent storage
+      raise PicklingError("Temporary objects can't be pickled")
+    return super(TemporaryDocumentMixin, self).__getstate__()
 
   def reindexObject(self, *args, **kw):
     pass

product/ERP5Type/tests/testERP5Type.py

@@ -31,8 +31,10 @@ other Tests are in erp5_core_test:testERP5Type) which is deprecated in favor
 of Portal Type as Classes and ZODB Components
 """
 
+import pickle
 import unittest
 import warnings
+from Acquisition import aq_base
 from Products.ERP5Type.tests.ERP5TypeTestCase import ERP5TypeTestCase
 from AccessControl.ZopeGuards import guarded_import
 from Products.ERP5Type.tests.utils import LogInterceptor
@@ -244,6 +246,19 @@ class TestERP5Type(ERP5TypeTestCase, LogInterceptor):
       self.assertTrue(o.isTempObject())
       self.assertTrue(guarded_import("Products.ERP5Type.Document", fromlist=["newTempBase"]))
 
+    def test_TempObjectPersistent(self):
+      # Temp objects can not be stored in ZODB
+      temp_object = self.portal.person_module.newContent(portal_type='Person', temp_object=True)
+      self.assertTrue(temp_object.isTempObject())
+
+      # they can be pickled
+      self.assertTrue(pickle.dumps(aq_base(temp_object)))
+
+      # but they can not be saved in ZODB accidentally
+      self.portal.person_module.oops = temp_object
+      self.assertRaisesRegexp(Exception, "Temporary objects can't be pickled", self.commit)
+      self.abort()
+
     def test_warnings_redirected_to_event_log(self):
       self._catch_log_errors()
       self.addCleanup(self._ignore_log_errors)