[FIX] base: Contacts still have deactivated language

Steps to reproduce the bug:
- Install web_studio, contacts
- Activate language English (UK)
- Switch all users' language to UK
- Deactivate language English (US)
- Via Studio, add a related field to a contact: Self > Language

Bug:
Traceback: contacts still have en_US as language and it's deactivated.

opw:2350362

closes odoo/odoo#60279

X-original-commit: 47ec3585f50f030025b39031807be50a9299bcd6
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>
Signed-off-by: backspac <backspac@users.noreply.github.com>

odoo/addons/base/i18n/base.pot

@@ -9074,6 +9074,12 @@ msgid ""
 "records manually and try importing again."
 msgstr ""
 
+#. module: base
+#: code:addons/base/models/res_lang.py:0
+#, python-format
+msgid "Cannot deactivate a language that is currently used by contacts."
+msgstr ""
+
 #. module: base
 #: code:addons/base/models/res_lang.py:0
 #, python-format

odoo/addons/base/models/res_lang.py

@@ -278,8 +278,10 @@ class Lang(models.Model):
         if 'code' in vals and any(code != vals['code'] for code in lang_codes):
             raise UserError(_("Language code cannot be modified."))
         if vals.get('active') == False:
-            if self.env['res.users'].search([('lang', 'in', lang_codes)]):
+            if self.env['res.users'].search_count([('lang', 'in', lang_codes)]):
                 raise UserError(_("Cannot deactivate a language that is currently used by users."))
+            if self.env['res.partner'].search_count([('lang', 'in', lang_codes)]):
+                raise UserError(_("Cannot deactivate a language that is currently used by contacts."))
             # delete linked ir.default specifying default partner's language
             self.env['ir.default'].discard_values('res.partner', 'lang', lang_codes)
 

odoo/addons/base/tests/test_translate.py

@@ -437,7 +437,7 @@ class TestTranslationWrite(TransactionCase):
 
     def test_03_fr_single(self):
         self.env['res.lang']._activate_lang('fr_FR')
-        self.env['res.users'].with_context(active_test=False).search([]).write({'lang': 'fr_FR'})
+        self.env['res.partner'].with_context(active_test=False).search([]).write({'lang': 'fr_FR'})
         self.env.ref('base.lang_en').active = False
 
         langs = self.env['res.lang'].get_installed()
@@ -483,7 +483,7 @@ class TestTranslationWrite(TransactionCase):
     def test_04_fr_multi_no_en(self):
         self.env['res.lang']._activate_lang('fr_FR')
         self.env['res.lang']._activate_lang('es_ES')
-        self.env['res.users'].with_context(active_test=False).search([]).write({'lang': 'fr_FR'})
+        self.env['res.partner'].with_context(active_test=False).search([]).write({'lang': 'fr_FR'})
         self.env.ref('base.lang_en').active = False
 
         langs = self.env['res.lang'].get_installed()