Crash on nil chunks with message/rfc822 mail with invalid Content-Transfer-Encoding

[alech]

I recently received a mail with the following structure:

From: foo@example.org
MIME-Version: 1.0
Content-type: multipart/report; boundary="======11647==82899======"; report-type="spam-notification"
Subject: Important

This is a multi-part message in MIME format...

--======11647==82899======
Content-Type: text/plain; charset="ISO-8859-1"
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable


--======11647==82899======
Content-Type: message/rfc822
Content-Disposition: attachment
Content-Transfer-Encoding: binary


--======11647==82899======--

After polling, sup crashed on me:

--- NoMethodError from thread: poll after loading inbox
private method `select' called for nil:NilClass
/usr/local/src/sup/lib/sup/message.rb:338:in `indexable_chunks'
/usr/local/src/sup/lib/sup/message.rb:334:in `indexable_body'
/usr/local/src/sup/lib/sup/index.rb:751:in `index_message_static'
/usr/local/src/sup/lib/sup/index.rb:714:in `sync_message'
/usr/local/src/sup/lib/sup/util.rb:649:in `method_missing'
/usr/local/src/sup/lib/sup/poll.rb:215:in `block in poll_from'
/usr/local/src/sup/lib/sup/maildir.rb:150:in `block in poll'
/usr/local/src/sup/lib/sup/maildir.rb:149:in `each'
/usr/local/src/sup/lib/sup/maildir.rb:149:in `each_with_index'
/usr/local/src/sup/lib/sup/maildir.rb:149:in `poll'
/usr/local/src/sup/lib/sup/poll.rb:201:in `poll_from'
/usr/local/src/sup/lib/sup/poll.rb:146:in `block (2 levels) in do_poll'
/usr/local/src/sup/lib/sup/poll.rb:136:in `each'
/usr/local/src/sup/lib/sup/poll.rb:136:in `block in do_poll'
:10:in `synchronize'
/usr/local/src/sup/lib/sup/poll.rb:135:in `do_poll'
/usr/local/src/sup/lib/sup/util.rb:649:in `method_missing'
/usr/local/src/sup/lib/sup/modes/poll_mode.rb:15:in `poll'
/usr/local/src/sup/lib/sup/poll.rb:58:in `poll_with_sources'
/usr/local/src/sup/lib/sup/poll.rb:94:in `poll'
/usr/local/src/sup/lib/sup/util.rb:649:in `method_missing'
bin/sup:220:in `block (2 levels) in '
/usr/local/src/sup/lib/sup.rb:87:in `block in reporting_thread'

I tracked this down to the inner Content-Transfer-Encoding: binary header, which sup considers invalid, leading to a RMail::EncodingUnsupportedError in message_to_chunks() (and apparently a nil chunks somewhere in the message parsing, which I didn't track down completely). A quick patch in message.rb allowed this particular message to be added correctly, but the problem persists with really invalid Content-Transfer-Encodings. A minimal message to demonstrate this is the following:

From: foo@example.org
MIME-Version: 1.0
Subject: Content-Transfer-Encoding:-bug in sup
Content-Type: message/rfc822
Content-Transfer-Encoding: nosuchcontenttransferencoding

foo

[cro]

Will this problem go away when the switch to Mail from RMail is complete?

[gauteh]

Thanks for your detailed report and example emails. It would certainly be easier to fix after Rmail-to-Mail-migration (#127) (which is not ready). But the problem, I think, is in Sup not ending up with an empty array [] and rather a nil. If there is no text/lines for the chunk it should be displayed as an attachment in the thread-view.

[gauteh]

Could you test #210, I noticed that with a new debug message a chunks array would not be returned when a message could not be loaded. Your test messages have been added to the test-suite.

[alech]

Tested #210, works for me - thanks for patching so fast :-)

[gauteh]

Cool!