message.text throws exception with bad characters in attachment filename

[Res42]

Hi!

This is a reproduction of a real email from our system. Please remove .txt from the end of the file. I included it because otherwise Github didn't allow it to be uploaded.

bad character attachment.eml.txt

The problem is because of this filename: K�relem.pdf

Exception:

'Header' object has no attribute 'startswith'

Stacktrace:

File "/usr/local/lib/python3.12/site-packages/django_mailbox/models.py", line 483, in get_new_mail_all_mailboxes
for message in messages:
File "/usr/local/lib/python3.12/site-packages/django_mailbox/models.py", line 461, in get_new_mail
msg = self.process_incoming_message(message)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/django_mailbox/models.py", line 284, in process_incoming_message
message_received.send(sender=self, message=msg)
File "/usr/local/lib/python3.12/site-packages/django/dispatch/dispatcher.py", line 189, in send
response = receiver(signal=self, sender=sender, **named)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[...]

File "/usr/local/lib/python3.12/site-packages/django_mailbox/models.py", line 661, in text
return utils.get_body_from_message(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/django_mailbox/utils.py", line 106, in get_body_from_message
if part.get('content-disposition', '').startswith('attachment;'):

If I understand it right the problem is here:

https://github.com/coddingtonbear/django-mailbox/blob/a41768c1602fa94824bdd8f88483a7e303065f44/django_mailbox/utils.py#L106

part.get() can return a Header object or a string; and the code only supports the string case.

Workaround / solution:

I monkey patched the get_body_from_message function like this:

# [...]
if convert_header_to_unicode(part.get('content-disposition', '')).startswith('attachment;'):
# [...]

it seems to work with str() too:

# [...]
if str(part.get('content-disposition', '')).startswith('attachment;'):
# [...]

I can submit a PR for this fix but I don't know which is the better of these solutions (or something else entirely).

[Pietro395]

What version of django_mailbox are you using? If you are not using the latest one can you try 4.10.1?

I imported the message you attached but I can't reproduce the error, it seems ok

[Res42]

I was using 4.9.0 but I updated it to 4.10.1 and it still throws:

======================================================================
ERROR: test_messages_with_unicode_attachments_should_parse_1 (mailprocessor.tests.tests.UnicodeAttachmentTestCase.test_messages_with_unicode_attachments_should_parse_1)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "[...]\tests\tests.py", line 72, in test_messages_with_unicode_attachments_should_parse_1
    self.assertIsNotNone(message.text)
                         ^^^^^^^^^^^^
  File "[...]\.venv\Lib\site-packages\django_mailbox\models.py", line 678, in text
    return utils.get_body_from_message(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "[...]\.venv\Lib\site-packages\django_mailbox\utils.py", line 106, in get_body_from_message
    if part.get('content-disposition', '').startswith('attachment;'):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'Header' object has no attribute 'startswith'

I'll fork the repo and write a failing test for this.

[Res42]

Commit: https://github.com/Res42/django-mailbox/commit/232f03755568cf57647e3431921562b45ac7459a

Test failed on CI: https://github.com/Res42/django-mailbox/actions/runs/8830921371/job/24245072678

[Pietro395]

Commit: Res42@232f037

Test failed on CI: https://github.com/Res42/django-mailbox/actions/runs/8830921371/job/24245072678

You're right, I was using 'processincomingmessage' and for some reason this way I can't reproduce it if I call up the text property of the message.

If you want feel free to make a pull request, I think your first solution is fine