288826 - Broken attachment name in MIME header is not concatenated back

Status: RESOLVED INVALID

(Thunderbird :: Mail Window Front End, defect)

Description

[Tim Goranskiy]

User-Agent:       Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322)
Build Identifier: version 1.0+ (20050402)

I got a email message with the following MIME header for one of its attachments:

------------4B29B114E19E05
Content-Type: application/msword; name==?Windows-1251?B?
4OHo8vPw6OXt8uDsLCDv7vHy8+/g/vno7CDv7iDw5efz6/zy4PLg7CDF?=
    =?Windows-1251?B?w90uZG9j?=
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename==?Windows-1251?B?
4OHo8vPw6OXt8uDsLCDv7vHy8+/g/vno7CDv7iDw5efz6/zy4PLg7CDF?=
    =?Windows-1251?B?w90uZG9j?=

Thunderbird showed me (in the attachements pane) only the part of the name 
decoded from the first piece of the filename== ... CDF?=, while the second 
=? ... 9j?= was ignored. The same happened when I'v tried to save this 
attachment - Thunderbird has created a correct file, but with shortened name.


Reproducible: Always

Steps to Reproduce:
1. Open example eml file
2. Try to save the second attachement file


Actual Results:  
And you'll get the "абитуриентам, поступающим по результатам Е" instead 
of "абитуриентам, поступающим по результатам ЕГЭ.doc" - the one, Outlook 
creates from the same message.

Comment 1

[Tim Goranskiy]

Attachment: Example eml file (zipped for smaller size)

Comment 2

[Tim Goranskiy]

Attachment: Screenshot of the MIME header

Comment 3

[Tim Goranskiy]

Attachment: Screenshot of how name is seen in Thunderbird

Comment 4

[Tim Goranskiy]

Attachment: Screenshot of how file is saved by Thunderbird compared to Outlook Express 6.0

Comment 5

[Mike Cowperthwaite]

That MIME header is illegal; headers are not allowed to be folded (broken) 
except where whitespace already exists in the header.  When unfolding a header, 
RFC2822 states explicitly that only the newline (CR/LF) should be removed, not 
any of the whitespace; and the embedded whitespace breaks the RFC2047 encoding.  
The problem is with the sending mail client (The Bat!).

Instead of using RFC2047 to encode the attachment name, the program should use 
RFC2231.
(Mozilla just recently implemented that same change -- see bug 193439.)