[xslt] possible bug in xsltproc/libxslt

[Iosif Fettich <ifettich netsoft ro>]

Hi,

hope to get a clue if I hit a bug or if I'm just doing something 
stupid/illegal.

I've attached an .xml file and an .xslt stylesheet.

I tried to simplfy this as much as possible, without loosing the relevance of 
the problem.

The output I get by running

$ xsltproc bug.xslt bug.xml

      Class 3
             Item 3, weight 1, position 1
             Item 1, weight 3, position 0
             Item 2, weight 2, position 1

isn't sorted as expected, based on the items weight.

It might be that there is no bug whatsoever and I'm just doing something 
illegal, however I couldn't so far get any evidence that the construct I'm 
using is flawed or not allowed.

I know now that the problem is related to the

<xsl:sort select="/root/items/item[ item_id = @it_id]/@weight"
                    order="descending"
                    data-type="number"/>

construct I'm using; the problem disappears if I do not try to select for 
sorting an value outside/above of the current node_set, but so far I just 
cannot convince me that this would be incorrect or illegal.


Many thanks,

Iosif Fettich

PS. Using Fedora Core 4,

$ rpm -qi libxslt
Name        : libxslt                      Relocations: /usr
Version     : 1.1.14                            Vendor: Red Hat, Inc.
Release     : 2                             Build Date: Lu 23 mai 2005 21:30:18 
EEST
Install Date: Sî 25 iun 2005 11:51:26 EEST      Build Host: 
tweety.build.redhat.com
Group       : Development/Libraries         Source RPM: 
libxslt-1.1.14-2.src.rpm
Size        : 1857109                          License: MIT
Signature   : DSA/SHA1, Mi 25 mai 2005 00:42:42 EEST, Key ID b44269d04f2a6fd2
Packager    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>
URL         : http://xmlsoft.org/XSLT/
Summary     : Library providing XSLT support.
Description :
This C library lets you transform XML files into other XML files (or
HTML, text, etc.) using the standard XSLT stylesheet transformation
mechanism. To use it, you need to have a versi
<root>
  <items>
    <item item_id="1" weight="3"/>
    <item item_id="2" weight="2"/>
    <item item_id="3" weight="1"/>
  </items>
  <classes>
    <class class_id="1" class_name="C1"/>
    <class class_id="2" class_name="C2"/>
    <class class_id="3" class_name="C3"/>
  </classes>
  <matches>
    <match cl_id="3" it_id="3"/> 
    <match cl_id="3" it_id="1"/> 
    <match cl_id="3" it_id="2"/> 
  </matches>
</root>

<?xml version="1.0" encoding="ISO-8859-1"?>



<xsl:stylesheet version="1.0" 

                xmlns:xsl="http://www.w3.org/1999/XSL/Transform";

                xmlns:exsl="http://exslt.org/common";

                extension-element-prefixes="exsl">



<xsl:output encoding="ISO-8859-1" 

            method="html" 

            omit-xml-declaration="yes" 

            indent="yes"/>



<xsl:template match="/">

  <xsl:for-each select="/root/classes/class">

    <xsl:variable name="class_id"             select="@class_id"/>

    <xsl:if test="count( /root/matches/match [ cl_id = $class_id ] ) >= 1">

      Class <xsl:value-of select="$class_id"/>

      <xsl:call-template name="show_one_class_items">

        <xsl:with-param name="class_id" select="$class_id"/>

      </xsl:call-template> 

    </xsl:if>  

  </xsl:for-each>

</xsl:template>



<xsl:template name="show_one_class_items">

  <xsl:param name="class_id"/>

        <xsl:for-each select="/root/matches/match[ @cl_id = $class_id]">

          <xsl:sort select="/root/items/item[ item_id = @it_id]/@weight" 

                    order="descending" 

                    data-type="number"/> 



          <xsl:variable name="item_id" select="@it_id"/>

          <xsl:variable name="position" select="position() mod 2"/>



          <xsl:for-each select="/root/items/item[ @item_id = $item_id ]">

             Item <xsl:value-of select="concat( $item_id, 

                                                ', weight ', @weight, 

                                                ', position ', $position)"/>

          </xsl:for-each>

        </xsl:for-each>

</xsl:template>

      

</xsl:stylesheet>