[Pkg-mailman-hackers] Bug#611804: Astonishing header mangling

[Ian Jackson]

Package: mailman
Version: 1:2.1.11-11+lenny1
Severity: serious

Mailman does stuff to the headers of messages which pass through it.
This can completely break the syntax and semantics of eg the CC
header.

Mailman should not edit existing headers _at all_.

For example, I sent this message (using Emacs VM):

  Date: Wed, 2 Feb 2011 13:00:59 +0000
  MIME-Version: 1.0
  Content-Type: text/plain; charset=us-ascii
  Content-Transfer-Encoding: 7bit
  To: test-list at chiark.greenend.org.uk
  Cc: Ian Jackson <Ian.Jackson at eu.citrix.com>, Ian Jackson
	  <ijackson+long.address at slimy.greenend.org.uk>, Some Person With
	  A Whole Paragraph Of Words Preceding Their Email Address Which
	  Will Make It Word Wrap <0ijacksonk.test at slimy.greenend.org.uk>,
	  Some Other Address <0ijacksonk.test2 at slimy.greenend.org.uk>
  Subject: Re: Test message
  In-Reply-To: <19785.18559.624449.560200 at mariner.uk.xensource.com>
  References: <19785.18559.624449.560200 at mariner.uk.xensource.com>
  X-Mailer: VM 8.0.9 under Emacs 22.2.1 (i486-pc-linux-gnu)

  Body.

What arrived the other side of mailman and exim4 was this:

  From test-list-bounces at chiark.greenend.org.uk Wed Feb 02 13:01:00 2011
  Return-path: <test-list-bounces at chiark.greenend.org.uk>
  Envelope-to: ijackson at chiark.greenend.org.uk
  Received: from localhost
	  ([127.0.0.1] helo=chiark.greenend.org.uk ident=list)
	  by chiark.greenend.org.uk (Debian Exim 4.69 #1) with esmtp
	  (return-path test-list-bounces at chiark.greenend.org.uk)
	  id 1PkcKS-0008Cm-RN; Wed, 02 Feb 2011 13:01:00 +0000
  Received: by chiark.greenend.org.uk (Debian Exim 4.69 #1) with local
	  (return-path ijackson at chiark.greenend.org.uk)
	  id 1PkcKR-0008Bl-BP; Wed, 02 Feb 2011 13:00:59 +0000
  Message-ID: <19785.21899.335155.540143 at chiark.greenend.org.uk>
  MIME-Version: 1.0
  In-Reply-To: <19785.18559.624449.560200 at mariner.uk.xensource.com>
  References: <19785.18559.624449.560200 at mariner.uk.xensource.com>
  X-Mailer: VM 8.0.9 under Emacs 22.2.1 (i486-pc-linux-gnu)
  X-BeenThere: test-list at chiark.greenend.org.uk
  X-Mailman-Version: 2.1.11
  Precedence: list
  List-Id: "test mailing list, not archived" <test-list.chiark.greenend.org.uk>
  List-Unsubscribe: <http://www.chiark.greenend.org.uk/mailman/options/test-list>, 
	  <mailto:test-list-request at chiark.greenend.org.uk?subject=unsubscribe>
  List-Post: <mailto:test-list at chiark.greenend.org.uk>
  List-Help: <mailto:test-list-request at chiark.greenend.org.uk?subject=help>
  List-Subscribe: <http://www.chiark.greenend.org.uk/mailman/listinfo/test-list>, 
	  <mailto:test-list-request at chiark.greenend.org.uk?subject=subscribe>
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  Errors-To: test-list-bounces at chiark.greenend.org.uk
  From: Ian Jackson <ijackson at chiark.greenend.org.uk>
  Sender: test-list-bounces at chiark.greenend.org.uk
  To: test-list at chiark.greenend.org.uk
  Cc: A at chiark.greenend.org.uk, Some Other Address <0ijacksonk.test2 at slimy.greenend.org.uk>,
	  Will Make It Word Wrap <0ijacksonk.test at slimy.greenend.org.uk>,
	  Ian Jackson <Ian.Jackson at eu.citrix.com>,
	  Ian Jackson <ijackson+long.address at slimy.greenend.org.uk>, Some at chiark.greenend.org.uk
  Subject: Re: Test message
  Date: Wed, 2 Feb 2011 13:00:59 +0000

  Body.

  _______________________________________________
  test-list maillist  -  test-list at chiark.greenend.org.uk
  http://www.chiark.greenend.org.uk/mailman/listinfo/test-list