[FIX] mail: check unicity inside alias names given for unicity check

In addition to checking conflicts with existing aliases, we have to check
that given name list also contains only unique names. Otherwise creating
in batch with duplicates raises the SQL unicity constraint instead of the
expected UserError.

Task-3453343 (Mail: Cleanup Alias Usage)
Prepares Task-36879 (Mail: Support MultiCompany Aliases)

Part-of: odoo/odoo#130632

addons/mail/models/mail_alias.py

@@ -194,11 +194,21 @@ class Alias(models.Model):
         :param list sanitized_names: a list of names (considered as sanitized
           and ready to be sent to DB);
         """
+        valid_names = list(filter(None, sanitized_names))
+
+        # list itself should be unique obviously
+        seen = set()
+        dupes = [name for name in valid_names if name in seen or seen.add(name)]
+        if dupes:
+            raise UserError(
+                _('Email aliases %(alias_name)s cannot be used on several records at the same time. Please update records one by one.',
+                  alias_name=', '.join(dupes))
+            )
+
         catchall_alias = self.env['ir.config_parameter'].sudo().get_param('mail.catchall.alias')
         bounce_alias = self.env['ir.config_parameter'].sudo().get_param('mail.bounce.alias')
         alias_domain = self.env["ir.config_parameter"].sudo().get_param("mail.catchall.domain")
         valid_domain_aliases = filter(None, (bounce_alias, catchall_alias))
-        valid_names = list(filter(None, sanitized_names))
 
         # matches catchall or bounce alias
         for sanitized_name in sanitized_names:

addons/test_mail/tests/test_mail_alias.py

@@ -117,6 +117,14 @@ class TestMailAlias(TestMailAliasCommon):
                 'alias_model_id': alias_model_id,
                 'alias_name': 'unused.test.alias',
             })
+        with self.assertRaises(exceptions.UserError), self.cr.savepoint():
+            self.env['mail.alias'].create([
+                {
+                    'alias_model_id': alias_model_id,
+                    'alias_name': alias_name,
+                }
+                for alias_name in ('new.alias.1', 'new.alias.2', 'new.alias.1')
+            ])
         with self.assertRaises(psycopg2.errors.UniqueViolation), self.cr.savepoint(), mute_logger('odoo.sql_db'):
             new_mail_alias.copy({'alias_name': 'unused.test.alias'})
         with self.assertRaises(exceptions.UserError), self.cr.savepoint():