[FIX] calendar: Select correct base event when current is archived

When the base event is archived, it continues being the base event
of the recurrence, and when trying to change the recurrence of all
the events of the recurrence, an error is thrown or some inconsistencies
occur.

To test the problem, you can follow these steps:

1. Create a recurrence of events from a non included day on the
   recurrence (example: recurrence on tuesday and friday and the start
   of the recurrence on monday). The first event will be archived
   automatically.
2. Open other event of the recurrence.
3. Modify the recurrence for all events (example: change the weekdays,
   set just tuesday instead of tuesday and friday)

An error will be thrown.

By making these changes, the base event will be updated, as
indicated in the _select_new_base_event method, so these
inconsistencies will not occur when making the changes.

closes #149349

Signed-off-by: Arnaud Joset (arj) <arj@odoo.com>

addons/calendar/models/calendar_event.py

@@ -555,6 +555,14 @@ def write(self, values):
                     self.env.ref('calendar.calendar_template_meeting_changedate', raise_if_not_found=False)
                 )
 
+        # Change base event when the main base event is archived. If it isn't done when trying to modify
+        # all events of the recurrence an error can be thrown or all the recurrence can be deleted.
+        if values.get("active") is False:
+            recurrences = self.env["calendar.recurrence"].search([
+                ('base_event_id', 'in', self.ids)
+            ])
+            recurrences._select_new_base_event()
+
         return True
 
     def _check_private_event_conditions(self):

addons/calendar/tests/test_event_recurrence.py

@@ -621,6 +621,48 @@ def test_unlink_recurrence_future(self):
         self.assertTrue(self.recurrence)
         self.assertEqual(self.events.exists(), self.events[0])
 
+    def test_recurrence_update_all_first_archived(self):
+        """Test to check the flow when a calendar event is
+        created from a day that does not belong to the recurrence.
+        """
+        event = self.env['calendar.event'].create({
+            'name': 'Recurrent Event',
+            'start': datetime(2019, 10, 22, 1, 0),
+            'stop': datetime(2019, 10, 22, 2, 0),
+            'recurrency': True,
+            'rrule_type': 'weekly',
+            'tue': False,
+            'wed': True,
+            'fri': True,
+            'interval': 1,
+            'count': 3,
+            'event_tz': 'Etc/GMT-4',
+        })
+        # Tuesday datetime(2019, 10, 22, 1, 0) - Archived
+        # Wednesday datetime(2019, 10, 23, 1, 0)
+        # Friday datetime(2019, 10, 25, 1, 0)
+        # Wednesday datetime(2019, 10, 30, 1, 0)
+        recurrence = self.env['calendar.recurrence'].search([('id', '!=', self.recurrence.id)])
+        events = recurrence.calendar_event_ids.sorted('start')
+        # Check first event is archived
+        self.assertFalse(event.active)
+        # Check base_event is different than archived and it is first active event
+        self.assertNotEqual(recurrence.base_event_id, event)
+        self.assertEqual(recurrence.base_event_id, events[0])
+        # Update all events to check that error is not thrown
+        events[0].write({
+            'recurrence_update': 'all_events',
+            'fri': False,
+        })
+        events = self.env['calendar.recurrence'].search(
+            [('id', '!=', self.recurrence.id)]
+        ).calendar_event_ids.sorted('start')
+        self.assertEventDates(events, [
+            (datetime(2019, 10, 23, 1, 0), datetime(2019, 10, 23, 2, 0)),
+            (datetime(2019, 10, 30, 1, 0), datetime(2019, 10, 30, 2, 0)),
+            (datetime(2019, 11, 6, 1, 0), datetime(2019, 11, 6, 2, 0)),
+        ])
+
 
 class TestUpdateMultiDayWeeklyRecurrentEvents(TestRecurrentEvents):