[IMP] mail, test_mail: allow to bypass user / channel group-based subscription

A context key is added allowing to bypass user / channel synchronization
when creating users. This is used notably in tests to avoid subscribing
new test users to "general" channel created as default data.

Purpose is to avoid interferences in query-based performance tests. It also
avoids unnecessary data creation and/or update when it is not necessary
especially in tests.

LINKS

Task ID-2070632 (main task)
Task ID-2419762 (followup task)
COM PR odoo/odoo#62859
ENT PR odoo/enterprise#15172
UPG PR odoo/upgrade#2005

addons/mail/models/res_users.py

@@ -80,8 +80,9 @@ GROUP BY channel_moderator.res_users_id""", [tuple(self.ids)])
                 raise exceptions.RedirectWarning(msg, action.id, _('Go to the configuration panel'))
 
         users = super(Users, self).create(vals_list)
-        # Auto-subscribe to channels
-        self.env['mail.channel'].search([('group_ids', 'in', users.groups_id.ids)])._subscribe_users()
+        # Auto-subscribe to channels unless skip explicitly requested
+        if not self.env.context.get('mail_channel_nosubscribe'):
+            self.env['mail.channel'].search([('group_ids', 'in', users.groups_id.ids)])._subscribe_users()
         return users
 
     def write(self, vals):

addons/test_mail/tests/test_performance.py

@@ -18,6 +18,7 @@ class BaseMailPerformance(TransactionCaseWithUserDemo):
             'mail_create_nolog': True,
             'mail_create_nosubscribe': True,
             'mail_notrack': True,
+            'mail_channel_nosubscribe': True,
         }
         self.user_employee = self.env['res.users'].with_context(self._quick_create_ctx).create({
             'name': 'Ernest Employee',