bug#13329: 24.2 post patch for #9521; Rmail forward does not correctly handle MIME messages containing "From " lines

[Mark Lillibridge]

Eli Zaretskii <eliz@gnu.org> writes:

>  > Cc: larsi@gnus.org, 13329@debbugs.gnu.org
>  > Date: Mon, 10 Oct 2022 22:03:51 +0300
>  > From: Eli Zaretskii <eliz@gnu.org>
>  > 
>  > > From: Mark Lillibridge <mdl@alum.mit.edu>
>  > > Cc: eliz@gnu.org, larsi@gnus.org, 13329@debbugs.gnu.org
>  > > Date: Mon, 10 Oct 2022 11:25:55 -0700
>  > > 
>  > > 
>  > >     If you don't want to start with an existing mbox, send a message to
>  > > yourself containing a line like "From nothing" in the body.  You will
>  > > see that a > incorrectly shows up in the Rmail display due to bug
>  > > #13328.
>  > 
>  > I just did, and I don't see the bug (in Emacs 28.2).  The mbox file I
>  > get does include a line that begins with ">From", but in the message
>  > buffer presented by Rmail to me I see just "From", with the ">"
>  > removed.
>  > 
>  > I see the same in Emacs 28.1, so I'm unsure why you see the problem
>  > there.  Maybe the reproduction recipe above is too simple, and
>  > something else is missing to reproduce the problem?
>  
>  And now I've also sent to myself a message with a MIME attachment,
>  where the attachment was a text that included a line that began with a
>  "From".  In the message I received, if I tell Rmail to show the
>  attachment, I see that line without any leading ">" before "From".  So
>  again, I'm unable to reproduce the problem you are describing.

    How did your mailer encode the attachment?  If it used base64, then
I don't expect you'll see the bug.


>  Are you sure you are using rmail.el which came with Emacs 28?

    For the test with the existing mbox, yes.  I downloaded and built
from source Emacs 28.1 and invoked it with -q, which should mean it
looks at none of my elisp.

- Mark