Pay invoice ask wizard displays wrong write off amount sometimes
Sometimes when paying an invoice in a currency that is different to the company currency the Write-Off amount that is displayed in the PayInvoiceAsk view is incorrect. This only happens when there has already been a part payment made, and is because the write off amount does not appear to include the payments that have already been made.
I think that it is because the on_change_lines method does not take the payment lines into account when recalculating the write off amount?