[IMP] mail: add tests about replies to internal note through mailgateway

Replying to internal notes should create internal notes and should
not notify anyone. Future commit will change that behavior. This
commit ensure the current behavior is working as intended.

addons/mail/tests/test_mail_features.py

@@ -2,6 +2,7 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 from odoo.addons.mail.tests.common import TestMail
+from odoo.addons.mail.tests.test_mail_gateway import MAIL_TEMPLATE_PLAINTEXT
 from odoo.tools import mute_logger
 
 
@@ -182,6 +183,27 @@ class TestMessagePost(TestMail):
         self.assertEqual(new_msg.parent_id.id, parent_msg.id, 'message_post: flatten error')
         self.assertFalse(new_msg.partner_ids)
 
+    @mute_logger('odoo.addons.mail.models.mail_mail')
+    def test_post_internal(self):
+        self.group_pigs.message_subscribe_users([self.user_admin.id])
+        msg = self.group_pigs.sudo(self.user_employee).message_post(
+            body='My Body', subject='My Subject',
+            message_type='comment', subtype='mt_note')
+        self.assertEqual(msg.partner_ids, self.env['res.partner'])
+        self.assertEqual(msg.needaction_partner_ids, self.env['res.partner'])
+        self.assertEqual(self.group_pigs.message_ids, msg)
+
+        self.format_and_process(
+            MAIL_TEMPLATE_PLAINTEXT,
+            email_from=self.user_admin.email,
+            msg_id='<1198923581.41972151344608186800.JavaMail.diff1@agrolait.com>',
+            to='not_my_businesss@example.com',
+            extra='In-Reply-To:\r\n\t%s\n' % msg.message_id)
+        reply = self.group_pigs.message_ids - msg
+        self.assertTrue(reply)
+        self.assertEqual(reply.subtype_id, self.env.ref('mail.mt_note'))
+        self.assertEqual(reply.needaction_partner_ids, self.env['res.partner'])
+
     @mute_logger('odoo.addons.mail.models.mail_mail')
     def test_message_compose(self):
         composer = self.env['mail.compose.message'].with_context({