[Alpine-info] [PATCH] Attachment export extension handling

[Chris Wilson]

Hi all,

There seems to be a problematic interaction between Microsoft Office, 
Eudora, Alpine and OpenOffice.

A user sent me a Word OOXML document, with a docx extension, using 
"X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9". Eudora wrote the 
following attachment MIME part:

  --=====================_522238291==_
  Content-Type: application/msword; name="xxxxxxxTechTasksAptivate.docx";
   x-mac-type="42494E41"; x-mac-creator="4D535744"
  Content-Transfer-Encoding: base64
  Content-Disposition: attachment; filename="xxxxxxxTechTasksAptivate.docx"

Alpine (in alpine/mailpart.c) discards the original extension and uses the 
one from the mailcap database. In my case, that says:

  application/msword; soffice -no-oosplash -writer '%s'; edit=soffice 
  -no-oosplash -writer '%s'; test=test -n "$DISPLAY"; 
  description="Microsoft Word Document"; nametemplate=%s.doc

So Alpine writes out a filename like 
"/tmp/img-xxxxxxxTechTasksAptivate-20242.doc", i.e. using the extension 
.doc instead of .docx, and then calls OpenOffice.

OpenOffice tries to open the file as an old-style Word document, not a 
DOCX, because of the extension, and reports that the file is corrupt and 
refuses to open it.

I'm not sure where the fault is. Perhaps application/msword is not valid 
for docx files, so it was Eudora's fault. Perhaps OpenOffice should have 
looked at the file contents instead of trusting the extension, to figure 
out that it's actually a DOCX. However, Alpine gives me no option to 
change the file name before viewing it, so having received such an email, 
I'm stuck with it. This is not the only case of a mailer sending files 
with bad MIME types; I think Outlook is a frequent offender.

I wrote the following quick patch to preserve the original extension on 
the filename supplied by the sender, if any, overriding the official 
extension in mailcap. I don't know if this is a security risk, but I hope 
you will consider it for inclusion in Alpine.

Please let me know if I should submit this to a bug tracker somewhere, or 
what else I can do to increase its chances of acceptance.

Cheers, Chris.
-- 
Aptivate | http://www.aptivate.org | Phone: +44 1223 760887
The Humanitarian Centre, Fenner's, Gresham Road, Cambridge CB1 2ES

Aptivate is a not-for-profit company registered in England and Wales
with company number 04980791.
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