[FIX] website_sale: multi-website

The fix added in 3a0f05f334 doesn't work if an already existing user in company A
trys to modify his address on a website linked to company B. The form will try to change the company_id
of the res.partner which will then conflit with the company_id of the associated res.user, ultimately leading
to a UserError and a 500 error on the website.

opw-2025457

closes odoo/odoo#34262

Signed-off-by: Rémi Rahir (rar) <rar@odoo.com>

addons/website_sale/controllers/main.py

@@ -605,9 +605,12 @@ class WebsiteSale(ProductConfiguratorController):
         new_values['customer'] = True
         new_values['team_id'] = request.website.salesteam_id and request.website.salesteam_id.id
         new_values['user_id'] = request.website.salesperson_id and request.website.salesperson_id.id
-        new_values['company_id'] = request.website.company_id.id
         new_values['website_id'] = request.website.id
 
+        if order.partner_id.id == request.website.user_id.sudo().partner_id.id:
+            # If the partner is public, we assign the company of the website
+            new_values['company_id'] = request.website.company_id.id
+
         lang = request.lang if request.lang in request.website.mapped('language_ids.code') else None
         if lang:
             new_values['lang'] = lang