File name for invoice e-mail attachment differs from "View Invoice" one

[Simba]

I was curious to know if there was a specific reason that the PDF file that is generated and downloaded when clicking on "View Invoice" from an order in the admin interface receives a different file name than when the system sends an invoice to a customer as an attachment.  This may not be immediately visible if options like "Add current year to invoice number" and "Position of the year date -> Before the sequential number" are not set, but if they are, it's clear that the file name generation is different than the number in the body of the PDF.

From what I can tell, the file name generated for the e-mail attachment is set in classes/order/OrderHistory.php , in the function sendEmail.  It utilizes its own logic/method to generate it:

$file_attachement['invoice']['name'] = Configuration::get('PS_INVOICE_PREFIX', (int)$order->id_lang, null, $order->id_shop).sprintf('%06d', $order->invoice_number).'.pdf';

... instead of using something like:

$file_attachement['invoice']['name'] = $pdf->filename;

For consistency sake, wouldn't it make more sense to have the invoice file name generation be the same everywhere?

As another, small nit pick, "attachment" is not spelled with that extra e, so the $file_attachement variable name is slightly misspelled.

Edited March 24, 2018 by Simba (see edit history)