Bug 2681

Summary: MIME Multipart message fails to display if preamble is encoded
Product: Claws Mail (GTK 2) Reporter: Chistopher Hall <hsw>
Component: UI/Message ViewAssignee: users
Status: RESOLVED INVALID    
Severity: normal    
Priority: P3    
Version: 3.8.0   
Hardware: PC   
OS: Linux   
Attachments:
Description Flags
Sample email that causes the failure none

Description Chistopher Hall 2012-06-27 08:50:30 UTC 
If a message is in MIME format and the preamble is encoded
 e.g. Content-Type: base64
Then the entire message fails to display, and in the case of a multipart/alternative
none of the parts show up on the RHS icon bar.  There is only a message/rfc822 icon
which indicates the message size (1.20KB).

Expanding the message structure shows shows a multipart/alternative with size 152B
but the message window is still empty.

A test message is attached based on the sample from:
http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html


Version Info:

Claws 3.8.0

GTK+ 2.24.10 / GLib 2.32.3
Locale: en_GB.UTF-8 (charset: UTF-8)
Operating System: Linux 3.2.0-25-generic (x86_64)
Ubuntu 12.04 LTS
Comment 1 Chistopher Hall 2012-06-27 08:52:52 UTC 
Created attachment 1119 [details]
Sample email that causes the failure
Comment 2 Colin Leroy 2012-06-27 10:19:08 UTC 
Hi,

This is invalid according to the very paragraph you quote (7.2):

As stated in the definition of the Content-Transfer-Encoding field, no encoding other than "7bit", "8bit", or "binary" is permitted for entities of type "multipart". The multipart delimiters and header fields are always 7-bit ASCII in any case, and data within the body parts can be encoded on a part-by-part basis, with Content-Transfer-Encoding fields for each appropriate body part.
Comment 3 Chistopher Hall 2012-06-28 06:56:31 UTC 
Thanks for the quick response.

I know it is invalid it is just that I receive a lot of emails from Windows clients
which do this.  I suspect it when a eight bit character set is in use, such as big5.
It seems that all it would take would be to ignore any content-encoding header.

A quick test shows that renaming the header to:
X-IGNORE-Content-Transfer-Encoding: base64
and the message displays correctly.

So I wrote a script:
https://github.com/hxw/dotfiles/blob/master/bin/fix-mime-multipart.pl

which can be bound to an Action and added to the toolbar

Just added this in case anyone else has this problem