Allow attaching invoices to emails

src/pretix/base/services/orders.py

@@ -127,9 +127,13 @@ def mark_order_paid(order: Order, provider: str=None, info: str=None, date: date
     }, user=user, api_token=api_token)
     order_paid.send(order.event, order=order)
 
+    invoice = None
     if order.event.settings.get('invoice_generate') in ('True', 'paid') and invoice_qualified(order):
         if not order.invoices.exists():
-            generate_invoice(order)
+            invoice = generate_invoice(
+                order,
+                trigger_pdf=not send_mail or not order.event.settings.invoice_email_attachment
+            )
 
     if send_mail:
         with language(order.locale):
@@ -155,7 +159,8 @@ def mark_order_paid(order: Order, provider: str=None, info: str=None, date: date
             try:
                 order.send_mail(
                     email_subject, email_template, email_context,
-                    'pretix.event.order.email.order_paid', user
+                    'pretix.event.order.email.order_paid', user,
+                    invoices=[invoice] if invoice and order.event.settings.invoice_email_attachment else []
                 )
             except SendMailException:
                 logger.exception('Order paid email could not be sent')
@@ -502,9 +507,11 @@ def _perform_order(event: str, payment_provider: str, position_ids: List[str],
         order = _create_order(event, email, positions, now_dt, pprov,
                               locale=locale, address=addr, meta_info=meta_info)
 
+    invoice = order.invoices.last()  # Might be generated by plugin already
     if event.settings.get('invoice_generate') == 'True' and invoice_qualified(order):
-        if not order.invoices.exists():
-            generate_invoice(order)
+        if not invoice:
+            invoice = generate_invoice(order, trigger_pdf=not event.settings.invoice_email_attachment)
+            # send_mail will trigger PDF generation later
 
     if order.total == Decimal('0.00'):
         email_template = event.settings.mail_text_order_free
@@ -536,7 +543,8 @@ def _perform_order(event: str, payment_provider: str, position_ids: List[str],
     try:
         order.send_mail(
             email_subject, email_template, email_context,
-            log_entry
+            log_entry,
+            invoices=[invoice] if invoice and event.settings.invoice_email_attachment else []
         )
     except SendMailException:
         logger.exception('Order received email could not be sent')