#3325: attachment type misdetection for small .tar.gz
------------------------------+---------------------------------------------
Reporter: anto...@dyne.org | Owner: mutt-dev
Type: defect | Status: new
Priority: minor | Milestone:
Component: mutt | Version: 1.5.20
Keywords: |
------------------------------+---------------------------------------------
Hi,
we have found that there is an attachment type misdetection for a small
.tar.gz file, you can see the complete bug report on
http://bugs.debian.org/541241.
I had a look at your code and in sendlib.c the mutt_make_file_attach
function will take care of looking up the mime type, it will use
'mutt_lookup_mime_type', then based on the extension it will report the
mimetype back to mutt. Unfortunately .gz, .bz2 and other compressed
formats are not classified as mime types because they are 'encodings, so
you won't find anything in /etc/mime.types
In that case (i.e.: no content-type found in mime-type) you're trying to
guess if it's a binary file or not with this check
{{{
if (info->lobin == 0 || (info->lobin + info->hibin + info->ascii)/
info->lobin >= 10)
{
/*
* Statistically speaking, there should be more than 10% "lobin"
* chars if this is really a binary file...
*/
att->type = TYPETEXT;
att->subtype = safe_strdup ("plain");
}
else
{
att->type = TYPEAPPLICATION;
att->subtype = safe_strdup ("octet-stream");
}
}}}
in this particular case this small .tar.gz file has the following info
data:
{{{
(gdb) print *info
$5 = {hibin = 43584, lobin = 8102, crlf = 522, ascii = 29871, linemax =
2790, space = 0, binary = 1, from = 0, dot = 0, cr = 1}
(gdb)
}}}
Unfortunately this results in a percentage of lobin chars slightly bigger
than 10:
{{{
>>> (43584+8102+29871)/8102.0
10.066279930881263
>>>
}}}
so mutt believes that the attachment is not a binary file.
How could you fix this?
there are some options: you could link to libmagic and let libmagic cares
about the mime-types, otherwise you could add a check on
mutt_lookup_mime_type (sendlib.c) and cover the major encoding by
assigning them the content type of application/octet-stream (.gz, .zip and
.bz2 should be enough).
If you want I can propose a patch, probably libmagic is the best option
but I suppose that you don't want to introduce another dependency
Cheers
Antonio
--
Ticket URL: <http://dev.mutt.org/trac/ticket/3325>
Mutt <http://www.mutt.org/>
The Mutt mail user agent
--
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
