Fixed crasher when sending rfc822 messages as attachments. (#59)

Author: spookylukey

anymail/utils.py

@@ -171,6 +171,12 @@ def __init__(self, attachment, encoding):
         if isinstance(attachment, MIMEBase):
             self.name = attachment.get_filename()
             self.content = attachment.get_payload(decode=True)
+            if self.content is None:
+                if hasattr(attachment, 'as_bytes'):
+                    self.content = attachment.as_bytes()
+                else:
+                    # Python 2.7 fallback
+                    self.content = attachment.as_string().encode(self.encoding)
             self.mimetype = attachment.get_content_type()
 
             if get_content_disposition(attachment) == 'inline':

tests/test_mailgun_backend.py

@@ -1,6 +1,14 @@
 # -*- coding: utf-8 -*-
 
 from datetime import date, datetime
+try:
+    from email import message_from_bytes
+except ImportError:
+    from email import message_from_string
+
+    def message_from_bytes(s):
+        return message_from_string(s.decode('utf-8'))
+
 from email.mime.base import MIMEBase
 from email.mime.image import MIMEImage
 
@@ -14,7 +22,7 @@
 from anymail.message import attach_inline_image_file
 
 from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharingTestCasesMixin
-from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin
+from .utils import sample_image_content, sample_image_path, SAMPLE_FORWARDED_EMAIL, SAMPLE_IMAGE_FILENAME, AnymailTestMixin
 
 
 @override_settings(EMAIL_BACKEND='anymail.backends.mailgun.EmailBackend',
@@ -131,13 +139,27 @@ def test_attachments(self):
         mimeattachment.set_payload(pdf_content)
         self.message.attach(mimeattachment)
 
+        # And also with an message/rfc822 attachment
+        forwarded_email = message_from_bytes(SAMPLE_FORWARDED_EMAIL)
+        rfcmessage = MIMEBase("message", "rfc822")
+        rfcmessage.attach(forwarded_email)
+        self.message.attach(rfcmessage)
+
         self.message.send()
         files = self.get_api_call_files()
         attachments = [value for (field, value) in files if field == 'attachment']
-        self.assertEqual(len(attachments), 3)
+        self.assertEqual(len(attachments), 4)
         self.assertEqual(attachments[0], ('test.txt', text_content, 'text/plain'))
         self.assertEqual(attachments[1], ('test.png', png_content, 'image/png'))  # type inferred from filename
         self.assertEqual(attachments[2], (None, pdf_content, 'application/pdf'))  # no filename
+        # Email messages can get a bit changed with respect to
+        # whitespace characters in headers, without breaking the message, so we
+        # tolerate that:
+        self.assertEqual(attachments[3][0], None)
+        self.assertEqual(attachments[3][1].replace(b'\n', b'').replace(b' ', b''),
+                         (b'Content-Type: message/rfc822\nMIME-Version: 1.0\n\n' + SAMPLE_FORWARDED_EMAIL).replace(b'\n', b'').replace(b' ', b''))
+        self.assertEqual(attachments[3][2], 'message/rfc822')
+
         # Make sure the image attachment is not treated as embedded:
         inlines = [value for (field, value) in files if field == 'inline']
         self.assertEqual(len(inlines), 0)

tests/utils.py

@@ -52,6 +52,9 @@ def sample_image_content(filename=SAMPLE_IMAGE_FILENAME):
         return f.read()
 
 
+SAMPLE_FORWARDED_EMAIL = b'Received: by luna.mailgun.net with SMTP mgrt 8734663311733; Fri, 03 May 2013\n 18:26:27 +0000\nContent-Type: multipart/alternative; boundary="eb663d73ae0a4d6c9153cc0aec8b7520"\nMime-Version: 1.0\nSubject: Test email\nFrom: Someone <someone@example.com>\nTo: someoneelse@example.com\nReply-To: reply.to@example.com\nMessage-Id: <20130503182626.18666.16540@example.com>\nList-Unsubscribe: <mailto:u+na6tmy3ege4tgnldmyytqojqmfsdembyme3tmy3cha4wcndbgaydqyrgoi6wszdpovrhi5dinfzw63tfmv4gs43uomstimdhnvqws3bomnxw2jtuhusteqjgmq6tm@example.com>\nX-Mailgun-Sid: WyIwNzI5MCIsICJhbGljZUBleGFtcGxlLmNvbSIsICI2Il0=\nX-Mailgun-Variables: {"my_var_1": "Mailgun Variable #1", "my-var-2": "awesome"}\nDate: Fri, 03 May 2013 18:26:27 +0000\nSender: someone@example.com\n\n--eb663d73ae0a4d6c9153cc0aec8b7520\nMime-Version: 1.0\nContent-Type: text/plain; charset="ascii"\nContent-Transfer-Encoding: 7bit\n\nHi Bob, This is a message. Thanks!\n\n--eb663d73ae0a4d6c9153cc0aec8b7520\nMime-Version: 1.0\nContent-Type: text/html; charset="ascii"\nContent-Transfer-Encoding: 7bit\n\n<html>\n                            <body>Hi Bob, This is a message. Thanks!\n                            <br>\n</body></html>\n--eb663d73ae0a4d6c9153cc0aec8b7520--\n'
+
+
 # noinspection PyUnresolvedReferences
 class AnymailTestMixin:
     """Helpful additional methods for Anymail tests"""