420035 - Subject that is so long that it has to be encoded into multiple lines isn't properly decoded

Status: RESOLVED INVALID

(Thunderbird :: General, defect)

Description

[Ondrej Valek]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.12) Gecko/20080129 Iceweasel/2.0.0.12 (Debian-2.0.0.12-1)
Build Identifier: version 2.0.0.9 (20080110)

Our mails, created by Zend Framework Mail functions encode subject like this:
Subject: =?ISO-8859-2?Q?PREVIO=20-=20Registrace=20ubytovac=EDho=20za=F8=EDzen=ED=20-=20Briliant?=

Subject: =?ISO-8859-2?Q?PREVIO=20-=20Registrace=20ubytovac=EDho=20za=F8=EDzen=ED=20-=20Penzion=20+=20Relax=20centrum= =20Kub=ED=E8kovi?=

The first subject is shown correctly:
PREVIO - Registrace ubytovacího zařízení - Briliant

while the second one is displayed like this (i.e. not decoded):
=?ISO-8859-2?Q?PREVIO=20-=20Registrace=20ubytovac=EDho=20za=F8=EDzen=ED=20-=20Penzion=20+=20Relax=20centrum= =20Kub=ED=E8kovi?=



Reproducible: Always

Steps to Reproduce:
1.
2.
3.
Actual Results:  
Too long subject in non-ASCII charset encoded with quoted-printable encoding is displayed "not-decoded".

Expected Results:  
I expect the subject to be displayed decoded.

http://tools.ietf.org/html/rfc2047 says in the paragraph 2. Syntax of encoded-words:

An 'encoded-word' may not be more than 75 characters long, including
   'charset', 'encoding', 'encoded-text', and delimiters.  If it is
   desirable to encode more text than will fit in an 'encoded-word' of
   75 characters, multiple 'encoded-word's (separated by CRLF SPACE) may
   be used.

   While there is no limit to the length of a multiple-line header
   field, each line of a header field that contains one or more
   'encoded-word's is limited to 76 characters.

It seems to me, that Thunderbird has a problem with decoding such subjects, which  are encoded into multiple lines.

Comment 1

[Magnus Melin [:mkmelin]]

>    desirable to encode more text than will fit in an 'encoded-word' of
>   75 characters, multiple 'encoded-word's (separated by CRLF SPACE) may
>   be used.

Yes, but in your example the first row doesn't end with ?= and the next line doesn't start with =?ISO-8859-2, so it's not encoded words.

Looks invalid to me...

Comment 2

[Ondrej Valek]

You're right. I wasn't able to tell from the first sight where the problem was, whther on TB side or Zend side. Now that I tried also MS Outlook I see that there's a problem with Zend mail.

Marking the bug as invalid.

Comment 3

[Krisztian]

I receive too many such e-mails... For example:

Subject: =?iso-8859-2?Q?Kyocera - Penge=E9les precizit=E1s! Aj=E1nd=E9k kyocera
 ker=E1mia k=E9s szett!?=


This might be improper encoding on the sender's side, but as it happens quite often, would be good to get Thunderbird be able to decode it.