[MOV] (mass_)mail(_ing): move 'model_is_thread' field to mail

This field will be used to remove low-level asserts using existence of
'message_post' on a given model instead of correctly checking the
inheritance on mail.thread.

This is going to increase a bit query counters but those queries should
be fast and have no real impact on performances.

Task-2088884 (Mail: Use editable computed stored fields in composer)

Part-of: odoo/odoo#107356

addons/mail/wizard/mail_compose_message.py

@@ -149,6 +149,7 @@ class MailComposer(models.TransientModel):
     composition_batch = fields.Boolean(
         'Batch composition', compute='_compute_composition_batch')  # more than 1 record (raw source)
     model = fields.Char('Related Document Model')
+    model_is_thread = fields.Boolean('Thread-Enabled', compute='_compute_model_is_thread')
     res_ids = fields.Text('Related Document IDs')
     res_domain = fields.Text('Active domain')
     res_domain_user_id = fields.Many2one(
@@ -227,6 +228,13 @@ class MailComposer(models.TransientModel):
             res_ids = composer._evaluate_res_ids()
             composer.composition_batch = len(res_ids) > 1 if res_ids else False
 
+    @api.depends('model')
+    def _compute_model_is_thread(self):
+        """ Determine if model is thread enabled. """
+        for composer in self:
+            model = self.env['ir.model']._get(composer.model)
+            composer.model_is_thread = model.is_mail_thread
+
     @api.depends('subtype_id')
     def _compute_subtype_is_log(self):
         """ In comment mode, tells whether the subtype is a note. Subtype has

addons/mail/wizard/mail_compose_message_views.xml

@@ -19,6 +19,7 @@
                         <field name="lang" invisible="1"/>
                         <field name="mail_server_id" invisible="1"/>
                         <field name="model" invisible="1"/>
+                        <field name="model_is_thread" invisible="1"/>
                         <field name="parent_id" invisible="1"/>
                         <field name="record_name" invisible="1"/>
                         <field name="render_model" invisible="1"/>

addons/mass_mailing/wizard/mail_compose_message.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
-from odoo import api, fields, models
+from odoo import fields, models
 
 
 class MailComposeMessage(models.TransientModel):
@@ -11,13 +11,6 @@ class MailComposeMessage(models.TransientModel):
     campaign_id = fields.Many2one('utm.campaign', string='Mass Mailing Campaign', ondelete='set null')
     mass_mailing_name = fields.Char(string='Mass Mailing Name', help='If set, a mass mailing will be created so that you can track its results in the Email Marketing app.')
     mailing_list_ids = fields.Many2many('mailing.list', string='Mailing List')
-    model_is_thread = fields.Boolean(compute='_compute_model_is_thread')
-
-    @api.depends('model')
-    def _compute_model_is_thread(self):
-        for composer in self:
-            model = self.env['ir.model']._get(composer.model)
-            composer.model_is_thread = model.is_mail_thread
 
     def _action_send_mail(self, auto_commit=False):
         """ Override to generate the mass mailing in case only the name was

addons/mass_mailing/wizard/mail_compose_message_views.xml

@@ -8,7 +8,6 @@
             <field name="inherit_id" ref="mail.email_compose_message_wizard_form"/>
             <field name="arch" type="xml">
                 <xpath expr="//field[@name='auto_delete_keep_log']" position="after">
-                    <field name="model_is_thread" invisible="1"/>
                     <field name="campaign_id" groups="mass_mailing.group_mass_mailing_campaign"
                         attrs="{'invisible': ['|', ('composition_mode', '!=', 'mass_mail'), ('model_is_thread', '!=', True)]}"/>
                     <field name="mass_mailing_name"