[FIX] sale_management: do not allow modification of non optional SOlines

The route used by the sale portal to update an option qty didn't check that
the modified SOline was effectively an option.

On the portal, only the optional lines were editable through the interface,
but through xmlrpc, a portal user could be able to remove/update the qty
of non optional lines from a quotation.

This is not a true security failure since only the quantity could be modified
through this route, but it makes sense to add a check to ensure this kind
of modification cannot happen.

closes odoo/odoo#88366

Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

addons/sale_management/controllers/portal.py

@@ -50,6 +50,10 @@ class CustomerPortal(portal.CustomerPortal):
         if not order_line or order_line.order_id != order_sudo:
             return False
 
+        if not order_line.sale_order_option_ids:
+            # Do not allow updating non optional lines from a quotation
+            return False
+
         if input_quantity is not False:
             quantity = input_quantity
         else: