[FIX] calendar: allow internal users to download invitation.ics

Access rights on ir.attachment depend on the record it is linked to.

steps to reproduce:
- log as admin
- create a calendar event and invite marc demo
- log as marc demo
- check discuss notifications and try to download "invite.ics"

before this commit:
- file can not be downloaded from the webclient (access error appear in logs)

after this commit:
- file can be downloaded from the webclient

opw-3754798

closes odoo/odoo#162694

X-original-commit: 6a698ef3ee99af45251156279c9a5af6185f5dd1
Signed-off-by: Arnaud Joset (arj) <arj@odoo.com>
Signed-off-by: Nicolas Danhier (nda) <nda@odoo.com>

addons/calendar/models/calendar_attendee.py

@@ -131,6 +131,8 @@ class Attendee(models.Model):
                         'datas': base64.b64encode(ics_file),
                         'description': 'invitation.ics',
                         'mimetype': 'text/calendar',
+                        'res_id': event_id,
+                        'res_model': 'calendar.event',
                         'name': 'invitation.ics',
                     }).ids
 

addons/calendar/tests/test_calendar.py

@@ -6,7 +6,7 @@ from datetime import date, datetime, timedelta
 
 from odoo import fields, Command
 from odoo.addons.base.tests.common import HttpCaseWithUserDemo
-from odoo.tests import Form, HttpCase, tagged
+from odoo.tests import Form, tagged, new_test_user
 from odoo.addons.base.tests.common import SavepointCaseWithUserDemo
 
 import freezegun
@@ -381,6 +381,23 @@ class TestCalendar(SavepointCaseWithUserDemo):
         # no more email should be sent
         _test_one_mail_per_attendee(self, partners)
 
+    def test_event_creation_internal_user_invitation_ics(self):
+        """ Check that internal user can read invitation.ics attachment """
+        internal_user = new_test_user(self.env, login='internal_user', groups='base.group_user')
+
+        partner = internal_user.partner_id
+        self.event_tech_presentation.write({
+            'partner_ids': [(4, partner.id)],
+        })
+        msg = self.env['mail.message'].search([
+            ('notified_partner_ids', 'in', partner.id),
+        ])
+        msg.invalidate_recordset()
+
+
+        # internal user can read the attachment without errors
+        self.assertEqual(msg.with_user(internal_user).attachment_ids.name, 'invitation.ics')
+
     def test_event_creation_sudo_other_company(self):
         """ Check Access right issue when create event with sudo