W3C home > Mailing lists > Public > public-xml-core-wg@w3.org > May 2006

Re: Canonicalization xml:base processing

From: John Cowan <cowan@ccil.org>
Date: Thu, 18 May 2006 11:45:04 -0400
To: Konrad Lanz <Konrad.Lanz@iaik.tugraz.at>
Cc: Richard Tobin <richard@inf.ed.ac.uk>, "Grosso, Paul" <pgrosso@ptc.com>, public-xml-core-wg@w3.org
Message-ID: <20060518154504.GD27118@ccil.org>

Konrad Lanz scripsit:

> Up front I'd like to mention that after talking to Jose Kahan and 
> thinking about the issue for a little longer we'd still prefer to also 
> perform "dot and dot-dot canonicalization" (aka. remove_dot_segments). 
> It will allow the reuse of existing implementations for relative URI 
> resolution. More important from my point of view however is: "dot and 
> dot-dot canonicalization" allows to map more equivalent documents onto 
> the same serialized output and helps to avoid false negatives in XMLDSig.

Unfortunately doing so produces inaccurate results.  For example, suppose
the outermost xml:base value is "foo/bar/" and the next inner one is
"../../..".  Ordinary remove_dot_segments will reduce this to the null
string, but this is incorrect.

Leaving it as "foo/bar/../../.." produces the same result as in the
original context when applied to an equivalent base URI.  It is only
safe to remove dots when that base URI is fully available.

The man that wanders far                        cowan@ccil.org
from the walking tree                           http://www.ccil.org/~cowan
        --first line of a non-existent poem by:         John Cowan
Received on Thursday, 18 May 2006 15:45:18 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:16:36 UTC