diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index c039ea2..9c18a2d 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -38,6 +38,14 @@ Features
backends (all but Amazon SES and SparkPost). Because this can expose API keys and
other sensitive info in log files, it should not be used in production.
+Fixes
+~~~~~
+
+* **Mailgun:** Fix problem where attachments with non-ASCII filenames would be lost.
+ (Works around Requests/urllib3 issue encoding multipart/form-data filenames in a way
+ that isn't RFC 7578 compliant. Thanks to `@decibyte`_ for catching the problem and
+ `@costela`_ for identifying the related Mailgun API oddity.)
+
v4.2
----
@@ -833,6 +841,8 @@ Features
.. _#115: https://github.com/anymail/issues/115
.. _@calvin: https://github.com/calvin
+.. _@costela: https://github.com/costela
+.. _@decibyte: https://github.com/decibyte
.. _@joshkersey: https://github.com/joshkersey
.. _@Lekensteyn: https://github.com/Lekensteyn
.. _@lewistaylor: https://github.com/lewistaylor
diff --git a/anymail/backends/mailgun.py b/anymail/backends/mailgun.py
index 3ba3eeb..7c2db20 100644
--- a/anymail/backends/mailgun.py
+++ b/anymail/backends/mailgun.py
@@ -1,4 +1,7 @@
from datetime import datetime
+from email.utils import encode_rfc2231
+
+from requests import Request
from ..exceptions import AnymailRequestsAPIError, AnymailError
from ..message import AnymailRecipientStatus
@@ -78,6 +81,35 @@ class MailgunPayload(RequestsPayload):
backend=self.backend, email_message=self.message, payload=self)
return "%s/messages" % self.sender_domain
+ def get_request_params(self, api_url):
+ params = super(MailgunPayload, self).get_request_params(api_url)
+ non_ascii_filenames = [filename
+ for (field, (filename, content, mimetype)) in params["files"]
+ if filename is not None and not isascii(filename)]
+ if non_ascii_filenames:
+ # Workaround https://github.com/requests/requests/issues/4652:
+ # Mailgun expects RFC 7578 compliant multipart/form-data, and is confused
+ # by Requests/urllib3's improper use of RFC 2231 encoded filename parameters
+ # ("filename*=utf-8''...") in Content-Disposition headers.
+ # The workaround is to pre-generate the (non-compliant) form-data body, and
+ # replace 'filename*={RFC 2231 encoded}' with 'filename="{UTF-8 bytes}"'.
+ # Replace _only_ the filenames that will be problems (not all "filename*=...")
+ # to minimize potential side effects--e.g., in attached messages that might
+ # have their own attachments with (correctly) RFC 2231 encoded filenames.
+ prepared = Request(**params).prepare()
+ form_data = prepared.body # bytes
+ for filename in non_ascii_filenames: # text
+ rfc2231_filename = encode_rfc2231( # wants a str (text in PY3, bytes in PY2)
+ filename if isinstance(filename, str) else filename.encode("utf-8"),
+ charset="utf-8")
+ form_data = form_data.replace(
+ b'filename*=%s' % rfc2231_filename.encode("utf-8"),
+ b'filename="%s"' % filename.encode("utf-8"))
+ params["data"] = form_data
+ params["headers"]["Content-Type"] = prepared.headers["Content-Type"] # multipart/form-data; boundary=...
+ params["files"] = None # these are now in the form_data body
+ return params
+
def serialize_data(self):
self.populate_recipient_variables()
return self.data
@@ -113,6 +145,7 @@ class MailgunPayload(RequestsPayload):
def init_payload(self):
self.data = {} # {field: [multiple, values]}
self.files = [] # [(field, multiple), (field, values)]
+ self.headers = {}
def set_from_email_list(self, emails):
# Mailgun supports multiple From email addresses
@@ -204,3 +237,15 @@ class MailgunPayload(RequestsPayload):
# Allow override of sender_domain via esp_extra
# (but pop it out of params to send to Mailgun)
self.sender_domain = self.data.pop("sender_domain", self.sender_domain)
+
+
+def isascii(s):
+ """Returns True if str s is entirely ASCII characters.
+
+ (Compare to Python 3.7 `str.isascii()`.)
+ """
+ try:
+ s.encode("ascii")
+ except UnicodeEncodeError:
+ return False
+ return True
diff --git a/tests/test_mailgun_backend.py b/tests/test_mailgun_backend.py
index 20f9e34..93da086 100644
--- a/tests/test_mailgun_backend.py
+++ b/tests/test_mailgun_backend.py
@@ -1,6 +1,8 @@
# -*- coding: utf-8 -*-
from datetime import date, datetime
+from textwrap import dedent
+
try:
from email import message_from_bytes
except ImportError:
@@ -171,9 +173,50 @@ class MailgunBackendStandardEmailTests(MailgunBackendMockAPITestCase):
def test_unicode_attachment_correctly_decoded(self):
self.message.attach(u"Une pièce jointe.html", u'\u2019
', mimetype='text/html')
self.message.send()
- files = self.get_api_call_files()
- attachments = [value for (field, value) in files if field == 'attachment']
- self.assertEqual(len(attachments), 1)
+
+ # Verify the RFC 7578 compliance workaround has kicked in:
+ data = self.get_api_call_data().decode("utf-8")
+ self.assertNotIn("filename*=", data) # No RFC 2231 encoding
+ self.assertIn(u'Content-Disposition: form-data; name="attachment"; filename="Une pièce jointe.html"', data)
+
+ files = self.get_api_call_files(required=False)
+ self.assertFalse(files) # files should have been moved to formdata body
+
+ def test_rfc_7578_compliance(self):
+ # Check some corner cases in the workaround that undoes RFC 2231 multipart/form-data encoding...
+ self.message.subject = u"Testing for filename*=utf-8''problems"
+ self.message.body = u"The attached message should have an attachment named 'vedhæftet fil.txt'"
+ # A forwarded message with its own attachment:
+ forwarded_message = dedent("""\
+ MIME-Version: 1.0
+ From: sender@example.com
+ Subject: This is a test message
+ Content-Type: multipart/mixed; boundary="boundary"
+
+ --boundary
+ Content-Type: text/plain
+
+ This message has an attached file with a non-ASCII filename.
+ --boundary
+ Content-Type: text/plain; name*=utf-8''vedh%C3%A6ftet%20fil.txt
+ Content-Disposition: attachment; filename*=utf-8''vedh%C3%A6ftet%20fil.txt
+
+ This is an attachment.
+ --boundary--
+ """)
+ self.message.attach(u"besked med vedhæftede filer", forwarded_message, "message/rfc822")
+ self.message.send()
+
+ data = self.get_api_call_data().decode("utf-8").replace("\r\n", "\n")
+ # Top-level attachment (in form-data) should have RFC 7578 filename (raw Unicode):
+ self.assertIn(
+ u'Content-Disposition: form-data; name="attachment"; filename="besked med vedhæftede filer"', data)
+ # Embedded message/rfc822 attachment should retain its RFC 2231 encoded filename:
+ self.assertIn("Content-Type: text/plain; name*=utf-8''vedh%C3%A6ftet%20fil.txt", data)
+ self.assertIn("Content-Disposition: attachment; filename*=utf-8''vedh%C3%A6ftet%20fil.txt", data)
+ # References to RFC 2231 in message text should remain intact:
+ self.assertIn("Testing for filename*=utf-8''problems", data)
+ self.assertIn(u"The attached message should have an attachment named 'vedhæftet fil.txt'", data)
def test_embedded_images(self):
image_filename = SAMPLE_IMAGE_FILENAME
diff --git a/tests/test_mailgun_integration.py b/tests/test_mailgun_integration.py
index e8b388d..6acbf59 100644
--- a/tests/test_mailgun_integration.py
+++ b/tests/test_mailgun_integration.py
@@ -1,3 +1,7 @@
+# -*- coding: utf-8 -*-
+
+from __future__ import unicode_literals
+
import os
import logging
import unittest
@@ -116,7 +120,7 @@ class MailgunBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
track_opens=True,
)
message.attach("attachment1.txt", "Here is some\ntext for you", "text/plain")
- message.attach("attachment2.csv", "ID,Name\n1,3", "text/csv")
+ message.attach("vedhæftet fil.csv", "ID,Name\n1,3", "text/csv")
cid = message.attach_inline_image_file(sample_image_path(), domain=MAILGUN_TEST_DOMAIN)
message.attach_alternative(
"This is the
html body
