Hello,
I want to modify the Purchase Receipt emails for some of my sales. The following filters are available, all placed within the edd_email_purchase_receipt() function in the includes/emails/functions.php file:
edd_purchase_from_name
edd_purchase_from_address
edd_purchase_subject
edd_purchase_heading
edd_purchase_receipt
All of the filters pass the $payment_id and the $payment_data arguments, except the edd_purchase_subject, which passes only the $payment_id argument. This is not a bug, but rather an inconsistency.
Of course the $payment_data can be derived from the $payment_id with just two lines of code, so the missing $payment_data in the edd_purchase_subject filter is not hindering me in my customization efforts. I only wanted to report this inconsistency, as it might be of interest for you.