945730 - Bogus «Content-Type: application/oct-stream» on outgoing messages

Status: RESOLVED DUPLICATE of bug 776246

(MailNews Core :: MIME, defect)

Description

[Tony Mechelynck [:tonymec]]

Mozilla/5.0 (X11; Linux x86_64; rv:27.0) Gecko/20100101 Firefox/27.0 SeaMonkey/2.24a1 ID:20130919003001 c-c:1ea1fc3586db m-c:803189f35921

(This is the latest SeaMonkey nightly for Linux64, see bug 943740)

While looking at the source of an email I just sent, with a PDF attachment added by SeaMonkey Mail, I notice the strange MIME type "application/oct-stream" instead of whatever would be normal for PDF, or at least of "application/octet-stream" (with octet- and not oct-). I am copying below the headers of the email in question (the "X-Mozilla-Keys:" header ends in a lot of spaces, which, when wrapped in this bug, might give the false impression of a spurious empty line), those of the text part, then those of the attachment; I attached the latter from a PDF file found on my HD:

From - Tue Dec 03 15:36:34 2013
X-Mozilla-Status: 0001
X-Mozilla-Status2: 00800000
X-Mozilla-Keys:                                                                                 
Message-ID: <[e-mail]>
Date: Tue, 03 Dec 2013 15:36:25 +0100
From: Tony Mechelynck <[e-mail]>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:27.0) Gecko/20100101 Firefox/27.0 SeaMonkey/2.24a1
MIME-Version: 1.0
To: JV-CONSULT <[e-mail]>
Subject: Sacs-poubelle sur la rue en dehors des heures (rue de Laeken 82-84)
References: <[e-mail]>
In-Reply-To: <[e-mail]>
Content-Type: multipart/mixed;
 boundary="------------050506000103030402090001"

This is a multi-part message in MIME format.
--------------050506000103030402090001
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

--------------050506000103030402090001
Content-Type: application/oct-stream;
 name="Impots Com.13.11.29.pdf"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename="Impots Com.13.11.29.pdf"

Comment 1

[rsx11m]

Check mimeTypes.rdf in your profile, you may have picked that up from an incoming message (in which case that's bug 503309, also see bug 462629).

Comment 2

[Tony Mechelynck [:tonymec]]

(In reply to rsx11m from comment #1)
> Check mimeTypes.rdf in your profile, you may have picked that up from an
> incoming message (in which case that's bug 503309, also see bug 462629).

Bingo! I see the following in mimeTypes.rdf (where […] means "some lines skipped, irrelevant to the case in point"):

[…]
  <RDF:Description RDF:about="urn:mimetype:handler:application/oct-stream"
                   NC:alwaysAsk="true"
                   NC:saveToDisk="false"
                   NC:useSystemDefault="false"
                   NC:handleInternal="false">
    <NC:externalApplication RDF:resource="urn:mimetype:externalApplication:application/oct-stream"/>
  </RDF:Description>
  […]
  <RDF:Seq RDF:about="urn:mimetypes:root">
    […]
    <RDF:li RDF:resource="urn:mimetype:application/oct-stream"/>
  </RDF:Seq>
  […]
  <RDF:Description RDF:about="urn:mimetype:externalApplication:application/oct-stream"
                   NC:path="/usr/local/bin/acroread"
                   NC:prettyName="acroread" />
  […]
  <RDF:Description RDF:about="urn:mimetype:application/oct-stream"
                   NC:value="application/oct-stream"
                   NC:editable="true"
                   NC:fileExtensions="pdf"
                   NC:description="PDF document">
    <NC:handlerProp RDF:resource="urn:mimetype:handler:application/oct-stream"/>
  </RDF:Description>
[…]


I suppose they make sense to handle incoming PDF attachments with an external Acrobat Reader application, but I still don't want them inserted on outgoing attachments, so I'm removing them (after copying mimeTypes.rdf to mimeTypes.rdf~).

Comment 3

[Tony Mechelynck [:tonymec]]

I notice similar lines in mimeTypes.rdf for another "strange" MIME type, viz. "application/octetstream" without dash, to be handled by Vim or gview; I'm removing them the same way.

Comment 4

[Tony Mechelynck [:tonymec]]

This bug looks more similar to bug 776246 (blocked by 503309), I'm changing the duplicate.

Comment 5

[Tony Mechelynck [:tonymec]]

P.S. mimeTypes.rdf edit (as in comment #2 and #3) requires a restart to make the spurious line disappear in "Edit → Preferences → Browser/Helper Applications".