Invoice date of draft invoices should always be the same as date sent

Draft invoices may get wrong invoice date

Description

Testing has shown that a draft invoice may be given an earlier invoice date than the final shipment date if a date is manually entered during editing of the draft invoice. This results in sent invoices having tax incorrect dates.

Expected behavior

• Invoice date should always be the same as the invoice shipment date.

• Manually fixing an earlier invoice date on draft invoices should be technically impossible.

Current behavior

• When a date is entered on a draft invoice, it remains, even when sent later.

• This can result in invoices with an incorrect date sequence.

Proposal

• Make it impossible to select an invoice date on draft invoices.

• Always have the invoice date automatically adopt the shipping date.