[FIX] website_sale: handle no partner address case

when purchasing products from website, if partner did not have a country set
the "pay now" button was broken. Now you get redirected to the billing form
to fill in your address.

addons/website_sale/controllers/main.py

@@ -617,6 +617,10 @@ class WebsiteSale(http.Controller):
         if order.partner_id.id == request.website.user_id.sudo().partner_id.id:
             return request.redirect('/shop/address')
 
+        for f in self._get_mandatory_billing_fields():
+            if not order.partner_id[f]:
+                return request.redirect('/shop/address?partner_id=%d' % order.partner_id.id)
+
         values = self.checkout_values(**post)
 
         # Avoid useless rendering if called in ajax