279907 - multipart/alternative: image/jpeg part displays: can't be overridden by As Plain Text

Status: RESOLVED WORKSFORME

(MailNews Core :: MIME, defect)

Description

[Nick Silkey]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0
Build Identifier: version 1.0 (20041206)

Only seen this once.  This spam e-mail contained an attached jpeg which
displayed in the body pane; preferences were set to plain text only.  In both
version 1.0 (20041206) under Windows XP and version 1.0 (20041221) under Linux.
 Display Attachments Inline was turned on.  The body pane would be empty and the
typical <hr>-like seperator between body and attachments was absent.   I was
able to rip out the entire message using mutt and have attached it below.  The
headers under both Thunderbird builds would stop after "X-SPAM-LEVEL", but the
mutt excavation shows much more was contained in the mail.

Reproducible: Always

Comment 1

[Nick Silkey]

Attachment: full mail in question - headers, body, attachment

Comment 2

[Mike Cowperthwaite]

The MIME structure of this document is:
  Top: multipart/alternative
    Part 1: multipart/alternative
      Part 1.1: text/plain
      Part 1.2: text/html   <- this appears to be text for fooling spam filters
    Part 2: image/jpeg      <- this is the ad

This structure is legal, and Mozilla is doing the expected thing with it: it 
displays the last part in the structure which it is capable of displaying.

I tried fudging the message to this:
  Top: multipart/alternative
    Part 1: text/plain
    Part 2: image/jpeg

and still could not get the text/plain portion to take precedence over the image 
portion.

Also, fwiw, this message exhibits the same symptom as bug 234980.

xref bug 130119.

Comment 3

[Ben Bucksch (:BenB)]

Our m/a decoder (mailnews/mime/src/mimemalt.cpp, IIRC) is very stupid: it just
skips some *known* unwanted mimetypes (esp. HTML) and hopes that the rest is
plaintext. (It wasn't me, although CVS blames me! ;-) )

<http://lxr.mozilla.org/seamonkey/source/mailnews/mime/src/mimemalt.cpp#226>

Comment 4

[Ben Bucksch (:BenB)]

> It wasn't me

(Actually, I don't know anymore)

Comment 5

[Mike Cowperthwaite]

Attachment: Another multipart that doesn't display quite right

While looking at bug 61815, I restructured the message that was there to follow
what might be a sensible MIME arrangement:
 Top: multipart/alternative
   Part 1: text/plain
   Part 2: multipart/related
     Part 2.1: text/html
     Part 2.2: image/gif

This displays the HTML part correctly, when that's selected.  When as-Plain is
selected, the message body is blank, but should be "testing".  I'm not sure if
this symptom is basically the same as this bug or not.

(There may be an error in this attachment, I edited it by hand.)

Comment 6

[Mike Cowperthwaite]

*** Bug 276899 has been marked as a duplicate of this bug. ***

Comment 7

[(not reading, please use [e-mail] instead)]

sorry for the spam.  making bugzilla reflect reality as I'm not working on these bugs.  filter on FOOBARCHEESE to remove these in bulk.

Comment 8

[Ludovic Hirlimann [:Usul]]

Nick this might have been fixed by bug 351224. Could you take a few minutes and download the latest nightly ( http://ftp.mozilla.org/pub/mozilla.org/thunderbird/nightly/latest-comm-central/ ), backup your profile and test and let us know if this is fixed or not ?

Comment 9

[Aleksander Machniak]

I found the same issue. Thunderbird 24.2.0 displays only the image part for message with following structure:
- multipart/alternative
   - text/plain
   - image/gif

"Message Body As" setting is irrelevant, i.e. does not change the behaviour.
What's more, the message contains:
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
	rv:24.0) Gecko/20100101 Thunderbird/24.2.0

Which might mean that Thunderbird also creates such "stupid" messages. I call it "stupid" because making an image/gif part alternative doesn't have much sense to me. Of course, it might have been broken by some server mail content filter that I'm not aware.

Comment 10

[Ben Bucksch (:BenB)]

I don't think TB sent this out. I've never seen this, and I can't imagine nor find such code. From superficial code inspection, there seems to be only one place that sets multipart:

http://mxr.mozilla.org/comm-central/source/mail/components/compose/content/MsgComposeCommands.js#2636
http://mxr.mozilla.org/comm-central/source/mailnews/compose/src/nsMsgSend.cpp#698

Comment 11

[Ludovic Hirlimann [:Usul]]

Removing myslef on all the bugs I'm cced on. Please NI me if you need something on MailNews Core bugs from me.

Comment 12

[Jorg K (CEST = GMT+2)]

With TB 49 (2016-05-17) the HTML part of attachment 172454 [details] is displayed, same for attachment 175206 [details].

Attachment 172454 [details] has a bad MIME structure. Attachment 175206 [details] is fine. That the text/plain part isn't displayed (comment #5) is covered by bug 253830.