[FIX] don't break when a partner has a user

mail_notification_email_template/models/mail_notification.py

@@ -68,3 +68,7 @@ class MailNotification(models.Model):
             )
             for a in etree.HTML(link_html or '<html/>').xpath('//a[@href]'):
                 this.record_access_link = a.get('href')
+
+    @api.model
+    def _get_access_link(self, mail, partner):
+        return self.env['mail.thread']._get_access_link(mail, partner)

mail_notification_email_template/tests/test_mail_notification_email_template.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 # © 2016 Therp BV <http://therp.nl>
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+from mock import patch
 from openerp.tests.common import TransactionCase
 
 
@@ -22,3 +23,9 @@ class TestMailNotificationEmailTemplate(TransactionCase):
         self.assertTrue(notifications)
         # check that our template was used
         self.assertTrue('<h2>Dear ' in n.body for n in notifications)
+        # check we can actually send our mail
+        with patch.object(
+                self.env['ir.mail_server'].__class__, 'send_email'
+        ) as mock_send_email:
+            notifications.send()
+            mock_send_email.assert_called()