[FIX] website_sale: store empty fields as False

If you specify an empty VAT number in the Contacts app, it will store it
as `False` in the ORM. If a new partner is created through the shop, the
VAT number is set through HTML form submission. It will use `''` for an
empty VAT number. When evaluating the VAT number in Python code, it will
usually be converted to a boolean, so it doesn't matter if it's `False`
or `''`. But in ORM queries those are two different values and code that
checks on `False` to check for the presence of a VAT number can
misinterpret `''` as being one.

This fix replaces `''` values submitted through the address form in the
shop with `False`.

opw-3114246

closes odoo#112807

Signed-off-by: Merel Geens <mege@odoo.com>

Author: mege-odoo

addons/website_sale/controllers/main.py

@@ -639,12 +639,21 @@ def _checkout_form_save(self, mode, checkout, all_values):
         return partner_id
 
     def values_preprocess(self, order, mode, values):
-        # Convert the values for many2one fields to integer since they are used as IDs
+        new_values = dict()
         partner_fields = request.env['res.partner']._fields
-        return {
-            k: (bool(v) and int(v)) if k in partner_fields and partner_fields[k].type == 'many2one' else v
-            for k, v in values.items()
-        }
+
+        for k, v in values.items():
+            # Convert the values for many2one fields to integer since they are used as IDs
+            if k in partner_fields and partner_fields[k].type == 'many2one':
+                new_values[k] = bool(v) and int(v)
+            # Store empty fields as `False` instead of empty strings `''` for consistency with other applications like
+            # Contacts.
+            elif v == '':
+                new_values[k] = False
+            else:
+                new_values[k] = v
+
+        return new_values
 
     def values_postprocess(self, order, mode, values, errors, error_msg):
         new_values = {}
@@ -742,7 +751,7 @@ def address(self, **kw):
                             (not order.only_services and (mode[0] == 'edit' and '/shop/checkout' or '/shop/address'))
                     # We need to update the pricelist(by the one selected by the customer), because onchange_partner reset it
                     # We only need to update the pricelist when it is not redirected to /confirm_order
-                    if kw.get('callback', '') != '/shop/confirm_order':
+                    if kw.get('callback', False) != '/shop/confirm_order':
                         request.website.sale_get_order(update_pricelist=True)
                 elif mode[1] == 'shipping':
                     order.partner_shipping_id = partner_id