[FIX] rating: check model is set before using it as key.

As message_notify can be done on empty recordset, message.res_id and
message.model can be Falsy. During filtering on rating messages, we need to
prevent the code to crash when filtering on those two properties and filter out
messages that are not linked to any record.

Task-2850521 (Knowledge: trash management)

closes odoo/odoo#99436

Related: odoo/enterprise#30908
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/rating/models/mail_message.py

@@ -28,7 +28,11 @@ class MailMessage(models.Model):
 
     def message_format(self, format_reply=True):
         message_values = super().message_format(format_reply=format_reply)
-        rating_mixin_messages = self.filtered(lambda message: issubclass(self.pool[message.model], self.pool['rating.mixin']))
+        rating_mixin_messages = self.filtered(lambda message:
+            message.model
+            and message.res_id
+            and issubclass(self.pool[message.model], self.pool['rating.mixin'])
+        )
         if rating_mixin_messages:
             ratings = self.env['rating.rating'].sudo().search([('message_id', 'in', rating_mixin_messages.ids), ('consumed', '=', True)])
             rating_by_message_id = dict((r.message_id.id, r) for r in ratings)