[FIX] mail: use template lang on layout and display name

Steps:
- Install sale
- Go to Settings / Translations / Languages
- Activate Dutch
- Go to Settings / Users & Companies / Users
- Edit demo
  - Language: Dutch
- Go to Sales
- Create a quotation:
  - Customer: demo
- Go to Settings / Technical / Automation / Scheduled Actions
- Create a new action:
  - Model: Sales Order
  - Python code:
  ```python
  last_id = model.search([], order='id desc', limit=1)[0].id
  env.ref('sale.email_template_edi_sale').send_mail(last_id, notif_layout='mail.mail_notification_paynow')
  ```
- Click "Run Manually"
- Go to Settings / Technical / Email / Emails
- Open the last email you just sent

Bug:
Parts of the email are not in Dutch

Explanation:
This commit makes a template pass the rendering language to the layout
and the display name when calling `template.send_mail()`.

opw:2467640

closes odoo/odoo#68656

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

2 files changed, 71 insertions, 1 deletions

diff --git a/addons/mail/models/mail_template.py b/addons/mail/models/mail_template.py
index d3363a8fd72..0e8e2cc855f 100644
--- a/addons/mail/models/mail_template.py
+++ b/addons/mail/models/mail_template.py
@@ -261,9 +261,16 @@ class MailTemplate(models.Model):
                 _logger.warning('QWeb template %s not found when sending template %s. Sending without layouting.' % (notif_layout, self.name))
             else:
                 record = self.env[self.model].browse(res_id)
+                model = self.env['ir.model']._get(record._name)
+
+                if self.lang:
+                    lang = self._render_lang([res_id])[res_id]
+                    template = template.with_context(lang=lang)
+                    model = model.with_context(lang=lang)
+
                 template_ctx = {
                     'message': self.env['mail.message'].sudo().new(dict(body=values['body_html'], record_name=record.display_name)),
-                    'model_description': self.env['ir.model']._get(record._name).display_name,
+                    'model_description': model.display_name,
                     'company': 'company_id' in record and record['company_id'] or self.env.company,
                     'record': record,
                 }
diff --git a/addons/test_mail/tests/test_mail_template.py b/addons/test_mail/tests/test_mail_template.py
index a845ffc0a79..5bf72f3da7c 100644
--- a/addons/test_mail/tests/test_mail_template.py
+++ b/addons/test_mail/tests/test_mail_template.py
@@ -54,6 +54,69 @@ class TestMailTemplate(TestMailCommon, TestRecipients):
         self.assertEqual(mail.email_cc, self.email_template.email_cc)
         self.assertEqual(mail.recipient_ids, self.partner_2 | self.user_admin.partner_id)
 
+    @mute_logger('odoo.addons.mail.models.mail_mail')
+    def test_template_translation(self):
+        self.env['res.lang']._activate_lang('es_ES')
+        self.env.ref('base.module_base')._update_translations(['es_ES'])
+
+        partner = self.env['res.partner'].create({'name': "test", 'lang': 'es_ES'})
+        email_template = self.env['mail.template'].create({
+            'name': 'TestTemplate',
+            'subject': 'English Subject',
+            'body_html': '<p>English Body</p>',
+            'model_id': self.env['ir.model']._get(partner._name).id,
+            'lang': '${object.lang}'
+        })
+        # Make sure Spanish translations have not been altered
+        description_translations = self.env['ir.translation'].search([('module', '=', 'base'), ('src', '=', partner._description), ('lang', '=', 'es_ES')])
+        description_translations.update({'value': 'Spanish description'})
+
+        self.env['ir.translation'].create({
+            'type': 'model',
+            'name': 'mail.template,subject',
+            'module': 'mail',
+            'lang': 'es_ES',
+            'res_id': email_template.id,
+            'value': 'Spanish Subject',
+            'state': 'translated',
+        })
+        self.env['ir.translation'].create({
+            'type': 'model',
+            'name': 'mail.template,body_html',
+            'module': 'mail',
+            'lang': 'es_ES',
+            'res_id': email_template.id,
+            'value': '<p>Spanish Body</p>',
+            'state': 'translated',
+        })
+        view = self.env['ir.ui.view'].create({
+            'name': 'test_layout',
+            'key': 'test_layout',
+            'type': 'qweb',
+            'arch_db': '<body><t t-raw="message.body"/> English Layout <t t-esc="model_description"/></body>'
+        })
+        self.env['ir.model.data'].create({
+            'name': 'test_layout',
+            'module': 'test_mail',
+            'model': 'ir.ui.view',
+            'res_id': view.id
+        })
+        self.env['ir.translation'].create({
+            'type': 'model_terms',
+            'name': 'ir.ui.view,arch_db',
+            'module': 'test_mail',
+            'lang': 'es_ES',
+            'res_id': view.id,
+            'src': 'English Layout',
+            'value': 'Spanish Layout',
+            'state': 'translated',
+        })
+
+        mail_id = email_template.send_mail(partner.id, notif_layout='test_mail.test_layout')
+        mail = self.env['mail.mail'].sudo().browse(mail_id)
+        self.assertEqual(mail.subject, 'Spanish Subject')
+        self.assertEqual(mail.body_html, '<body><p>Spanish Body</p> Spanish Layout Spanish description</body>')
+
     def test_template_add_context_action(self):
         self.email_template.create_action()