Re: [Exim] Interpreting Subject: lines - opinions, please

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Author: Frank S. Bernhardt
Date:  
To: exim-users
Subject: Re: [Exim] Interpreting Subject: lines - opinions, please
By changing the way $h_xxx expands do you risk breaking someone else's code?

Would creating a new variable such as $rfch_xxx solve this problem? This
way everything works as before but someone needing to search for
non-ASCII characters would simply use the new variable.

Philip Hazel wrote:
> The current state:
>
> The $h_xxx: expansion in Exim contains the actual content of the line,
> with leading/trailing white space removed, and commas inserted between
> multiple lines when the header is one that contains addresses. The
> $rh_xxx: expansion is the same, except that leading/trailing white
> space is not removed, and no commas are inserted.
>
> The cause of the problem:
>
> Header lines can be encoded according to RFC2047. The most common uses
> of this are to get non-ASCII characters into real names as part of
> addresses, and also to get such characters into Subject: lines.
>
> The problem:
>
> Exim does not interpret header lines that are encoded. Thus, for
> example, if a message contains the line
>
>     Subject: Internet café

>
> it might actually appear in the message as
>
>     Subject: =?iso-8859-1?Q?Internet_caf=E9?=

>
> This means that a user's filter file with a test such as
>
>     if $h_subject: contains "Internet café"

>
> won't work properly. Note that a string without any special characters
> could be encoded this way just to confuse things.
>
> The proposed solution:
>
> An Exim user has written a patch which causes the contents of header
> lines to be decoded according to the RFC 2047 rules before being put
> into a $h_xxx variable.
>
> I think this should be the default. We already have $rh_xxx for "raw"
> headers, so the basic text would remain available for anybody that
> needs it. However, this would be a (small?) incompatible change, which
> is is why I'm asking:
>
> Does anybody disagree?
>
> --
> Philip Hazel            University of Cambridge Computing Service,
> ph10@???      Cambridge, England. Phone: +44 1223 334714.

>
>
> --
>
> ## List details at http://www.exim.org/mailman/listinfo/exim-users Exim details at http://www.exim.org/ ##
>
>


--

Regards

Frank S. Bernhardt
b.c.s.i.
14 Halton Court
Markham, ON. Canada
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