Re: [xml] xmlXPathStringEvalNumber vs. atof

For our purposes, I am going to patch xpath.c(patch attached if you're interested) to preserve the parsing 
logic validating that the string conforms to the same grammar.  The patch removes all the numeric computation 
from the validation and instead calls atof on the validated string for the conversion to a double.

While the original problem I emailed about involved numbers that were not compliant with XPath 1.0, we found 
another example which I believe conforms to XPath 1.0 and returns an unexpected result.  The follow XPath 
returns false and I expect it to return true (2.7.2 on 64-bit Linux):

<xsl:value-of select=".30000000000004 = '.30000000000004'"/>

After applying my patch, it now returns true which would be the expected behaviour.  It also fixes the 
non-standard compliant example I provided in my original email.


----- "Bjoern Hoehrmann" <derhoermi gmx net> wrote:

* Christopher R. Palmer wrote:
* xmlXPathStringEvalNumber:
* @str:  A string to scan
*  [30a]  Float  ::= Number ('e' Digits?)?

Is that [30a] from some addendum to XPath 1.0 or is it a libxml

It would have to be an extension, new features cannot be added to W3C
recommendations without re-issuing the recommendation, which in case
of XPath 1.0 has not happened so far. Also, the "Errata" does not in-
clude it. It
seems has some
background on this.
BjÃrn HÃhrmann  mailto:bjoern hoehrmann de Â
Am Badedeich 7 Â Telefon: +49(0)160/4415681 Â
25899 DagebÃll  PGP Pub. KeyID: 0xA4357E78 Â

Attachment: libxml2-atof-2.7.3.patch
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