Fix activity retry settings for erp5_interface_post emails

In production, the sending of emails by using Internet Message Posts created activity failures : 

```
Node: activities-XX
Failures: 1
User name: 'System Processes'
Uid: 1234567890
Document: /erp5/person_module/XXXX
Method: Entity_sendEmail
Arguments: ()
Named Parameters: {'cc_url': None, 'from_url': None, 'event_relative_url': 'event_module/YYYY'}

Exception:
  Module Products.CMFActivity.Activity.SQLBase, line 607, in dequeueMessage
    transaction.commit()
  Module transaction._manager, line 123, in commit
    return self.get().commit()
  Module transaction._transaction, line 280, in commit
    reraise(t, v, tb)
  Module transaction._transaction, line 271, in commit
    self._commitResources()
  Module Products.TIDStorage.transaction_transaction, line 261, in _commitResources
    result = original__commitResources(self, *args, **kw)
  Module transaction._transaction, line 416, in _commitResources
    reraise(t, v, tb)
  Module transaction._transaction, line 393, in _commitResources
    rm.tpc_vote(self)
  Module ZODB.Connection, line 797, in tpc_vote
    s = vote(transaction)
  Module ZEO.ClientStorage, line 1072, in tpc_vote
    return self._check_serials()
  Module ZEO.ClientStorage, line 902, in _check_serials
    raise s
ReadConflictError: database read conflict error (oid 0x12345 serial this txn started with 0x12345 2018-05-16 06:27:17.471887, serial currently committed 0x12345 2018-05-16 06:53:10.977183)
``` 

This Merge Request proposes to allow Entity_sendEmail to be retried in case of ConflictError, as now Entity_sendEmail is doing more than what it used to be.

For this, we need to isolate the call to sendMailHostMessage to make sur that email won't be sent several times if the activity "Entity_sendEmail" is retried.

We also make sure that the activity created to send a message through MailHost gets the correct parameters to be never retried (retry_max=0 and retry_conflict=False)

/reviewed-on !672

bt5/erp5_base/SkinTemplateItem/portal_skins/erp5_base/Entity_sendEmail.py

@@ -33,4 +33,9 @@ create_post_message_method = event.getTypeBasedMethod('createPostMessage')
 if create_post_message_method:
   create_post_message_method(mail_message)
 else:
-  event.sendMailHostMessage(mail_message)
+  # We do not want to retry those activities, as sending email is not transactional safe
+  event.activate(
+    activity='SQLQueue',
+    conflict_retry=False,
+    max_retry=0
+  ).sendMailHostMessage(mail_message)

bt5/erp5_base/SkinTemplateItem/portal_skins/erp5_base/MailMessage_sendByActivity.py

-# We do not want to retry those activities, as sending email is not transactional safe
-activate_kw = kw.pop('activate_kw', {})
-activate_kw['max_retry'] = 0
-activate_kw['conflict_retry'] = False
 
 context.getPortalObject().portal_catalog.searchAndActivate(
   method_id="Entity_sendEmail",
   destination_related_uid=context.getUid(),
   method_kw=method_kw,
-  activate_kw=activate_kw,
+  activate_kw=kw.pop('activate_kw', {}),
   **kw)

bt5/erp5_interface_post/SkinTemplateItem/portal_skins/erp5_interface_post/ERP5Site_sendMailHostMessage.py

+# As a general rule, sending messages by MailHost should
+# be done in an activity context that never retry.
+# We do so because MailHost isn't transactional as the zodb.
+# This script should then always be called in an activity
+# spawned with parameters :
+#     conflict_retry=False,
+#     max_retry=0,
+
+context.getPortalObject().MailHost.send(data)

bt5/erp5_interface_post/SkinTemplateItem/portal_skins/erp5_interface_post/ERP5Site_sendMailHostMessage.xml

+<?xml version="1.0"?>
+<ZopeData>
+  <record id="1" aka="AAAAAAAAAAE=">
+    <pickle>
+      <global name="PythonScript" module="Products.PythonScripts.PythonScript"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>Script_magic</string> </key>
+            <value> <int>3</int> </value>
+        </item>
+        <item>
+            <key> <string>_bind_names</string> </key>
+            <value>
+              <object>
+                <klass>
+                  <global name="NameAssignments" module="Shared.DC.Scripts.Bindings"/>
+                </klass>
+                <tuple/>
+                <state>
+                  <dictionary>
+                    <item>
+                        <key> <string>_asgns</string> </key>
+                        <value>
+                          <dictionary>
+                            <item>
+                                <key> <string>name_container</string> </key>
+                                <value> <string>container</string> </value>
+                            </item>
+                            <item>
+                                <key> <string>name_context</string> </key>
+                                <value> <string>context</string> </value>
+                            </item>
+                            <item>
+                                <key> <string>name_m_self</string> </key>
+                                <value> <string>script</string> </value>
+                            </item>
+                            <item>
+                                <key> <string>name_subpath</string> </key>
+                                <value> <string>traverse_subpath</string> </value>
+                            </item>
+                          </dictionary>
+                        </value>
+                    </item>
+                  </dictionary>
+                </state>
+              </object>
+            </value>
+        </item>
+        <item>
+            <key> <string>_params</string> </key>
+            <value> <string>data</string> </value>
+        </item>
+        <item>
+            <key> <string>id</string> </key>
+            <value> <string>ERP5Site_sendMailHostMessage</string> </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+</ZopeData>

bt5/erp5_interface_post/SkinTemplateItem/portal_skins/erp5_interface_post/InternetMessagePost_export.py

-context.getPortalObject().MailHost.send(context.getData())
+# calling ERP5Site_sendMailHostMessage should be done in an activity
+# which NEVER retries.
+
+# internet_message_post_module because we need an object supporting
+# the activate method
+context.getPortalObject().internet_message_post_module.activate(
+  activity='SQLQueue',
+  conflict_retry=False,
+  max_retry=0,
+).ERP5Site_sendMailHostMessage(context.getData())

bt5/erp5_interface_post/TestTemplateItem/portal_components/test.erp5.testInterfacePost.py

@@ -28,6 +28,7 @@ import email
 import time
 
 from Products.ERP5Type.tests.ERP5TypeLiveTestCase import ERP5TypeTestCase
+from Products.ERP5Type.tests.utils import createZODBPythonScript, removeZODBPythonScript
 from Products.ERP5Type.tests.Sequence import SequenceList
 from Products.ZSQLCatalog.SQLCatalog import SimpleQuery
 from DateTime import DateTime
@@ -81,6 +82,14 @@ class TestInterfacePost(ERP5TypeTestCase):
       module = getattr(self.portal, module_id)
       module.manage_delObjects(list(module.objectIds()))
 
+    custom_skin = self.portal.portal_skins.custom
+    if 'Entity_sendEmail' in custom_skin.objectIds():
+      removeZODBPythonScript(
+        custom_skin,
+        'Entity_sendEmail',
+      )
+      self.commit()
+
   def _portal_catalog(self, **kw):
     result_list = self.portal.portal_catalog(**kw)
     uid_list = [x.uid for x in result_list]
@@ -333,6 +342,21 @@ class TestInterfacePost(ERP5TypeTestCase):
     pdf_document, = pdf_document_list
     self.assertEqual(2, int(pdf_document.getContentInformation()['Pages']))
 
+
+  def stepMakeEntitySendEmailFailOnce(self, sequence=None):
+    createZODBPythonScript(
+      self.portal.portal_skins.custom,
+      'Entity_sendEmail',
+      self.portal.Entity_sendEmail.params(),
+      """portal = context.getPortalObject()
+for activity in portal.portal_activities.getMessageList():
+  if activity.method_id == script.id:
+    if activity.retry == 0:
+      raise ValueError('Failure on purpose')
+    else:
+      return context.skinSuper('custom', script.id)(%s)""" % (self.portal.Entity_sendEmail.params(),)
+    )
+
   def test_emailSendingIsPilotedByInternetMessagePost(self):
     """
     """
@@ -392,6 +416,27 @@ class TestInterfacePost(ERP5TypeTestCase):
     sequence_list.addSequenceString(sequence_string)
     sequence_list.play(self)
 
+  def test_Entity_sendEmailCanRaiseOnceWithoutSpammingRecipient(self):
+    """
+    Entity_sendEmail used to be launched in an activity with retry_max=0 and
+    retry_conflict=False. But now that it creates Internet Message Posts, it
+    should be able to retry on ConflictError. We should also make sure that
+    in this case the mail isn't sent (as MailHost isn't transactional)
+    """
+    sequence_list = SequenceList()
+    sequence_string = """
+      stepMakeEntitySendEmailFailOnce
+      stepCreateMailMessage
+      stepStartMailMessage
+      stepCheckMailMessage
+      stepTic
+      stepCheckInternetMessagePostCreated
+      stepCheckOnlyOneMessageHasBeenSentFromMailHost
+      stepCheckLatestMessageListFromMailHost
+    """
+    sequence_list.addSequenceString(sequence_string)
+    sequence_list.play(self)
+
   def test_ingestedInternetMessagePostCreateMailMessageWithCausality(self):
     sequence_list = SequenceList()
     sequence_string = """