Missing invoice party on amendments
It is not possible to validate an amendment which updates any party values of a sale with invoice party set because it fails with a domain error.
Here are the steps to reproduce:
- Create a sale with party -> Customer and Invoice party: Invoice Customer
- Add a line for it, quote and confirm it
- Create a new amendment related to the sale created in step one with a line of type "Change party".
- Try to save the amendment
Current behaviour:
A domain error complaining that the invoice address is not valid is raised.
This is because we do not have the invoice_party on the amendments but we load the invoice address from this party.
Altought this behaviour is already present in released series I think the only way to fix is to add the invoice address field, so it can not be backported as it requires a database update.