Account Invoice Delete Attachment on Cancel

When a customer invoice is validated, on the first generation of the invoice report, a copy of the report is stored as attachment on the invoice. After that, every time a user asks for the Invoice report, it will be taken from the attachment. But, when a customer invoice/refund is cancelled, set back to draft, modified and re-validated, the Invoice report is still the old PDF file, which is often raised as a bug by the users.

With this module, when a customer invoice/refund is set back to draft, the attachment is deleted.

This module has been written by Alexis de Lattre from Akretion <alexis.delattre@akretion.com>.