[FIX] calendar: correct errors for default attendee

Step to reproduce:
- Create a lead
- go on the smart button meeting
- create a new meeting and edit it
- save

Current behaviour:
- Validation Error
- It seems the default_get apply command in onchange instead of passing the value which lead to missformed argument for meeting

Behaviour after PR:
- Do not send readonly attendee in calendar.event form view

opw-2724372

closes odoo/odoo#82794

X-original-commit: fba25d6982d149a9d5083f993dea7c2091736c58
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>
Signed-off-by: Arnaud Joset <arj@odoo.com>

addons/calendar/tests/test_attendees.py

@@ -108,3 +108,24 @@ class TestEventNotifications(TransactionCase):
         self.assertEqual(self.event.attendee_ids.partner_id, self.partner)
         self.assertTrue(self.event.invalid_email_partner_ids)
         self.assertEqual(self.event.invalid_email_partner_ids, self.partner)
+
+    def test_default_attendee(self):
+        """
+        Check if priority list id correctly followed
+        1) vals_list[0]['attendee_ids']
+        2) vals_list[0]['partner_ids']
+        3) context.get('default_attendee_ids')
+        """
+        partner_bis = self.env['res.partner'].create({'name': "Xavier"})
+        event = self.env['calendar.event'].with_user(
+            self.user
+        ).with_context(
+            default_attendee_ids=[(0, 0, {'partner_id': partner_bis.id})]
+        ).create({
+            'name': "Doom's day",
+            'partner_ids': [(4, self.partner.id)],
+            'start': datetime(2019, 10, 25, 8, 0),
+            'stop': datetime(2019, 10, 27, 18, 0),
+        })
+        self.assertIn(self.partner, event.attendee_ids.partner_id, "Partner should be in attendee")
+        self.assertNotIn(partner_bis, event.attendee_ids.partner_id, "Partner bis should not be in attendee")

addons/calendar/views/calendar_views.xml

@@ -219,7 +219,7 @@
 
                         <page name="page_invitations" string="Invitations" groups="base.group_no_one">
                             <button name="action_sendmail" type="object" string="Send Invitations" icon="fa-envelope" class="oe_link"/>
-                            <field name="attendee_ids" widget="one2many" mode="tree,kanban">
+                            <field name="attendee_ids" widget="one2many" mode="tree,kanban" readonly="1">
                                 <tree string="Invitation details" editable="top" create="false" delete="false">
                                     <field name="partner_id" />
                                     <field name="email" widget="email"/>