[xsl] Varied Results with Different Versions of Xalan, But How?

["Renick, Garrel" <garrel@xxxxxxxx>]

I have an odd problem that seems unexplainable. I'm seeing different
results of a simple transformation using xalan-j_2_6_0 (and prior
versions) versus xalan-j_2_7_0. The xalan-j_2_7_0 version results in
duplicated output. I'm using jdk1.5.0_12. Here are examples:

XML:
<?xml version='1.0'?>
<document>
 <permission>
  <grp gid="101" name="group1"/>
  <grp gid="102" name="group2"/>
 </permission>
</document>

XSLT:
<?xml version="1.0"?>
<xsl:stylesheet  xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
version="1.0">
  <xsl:output  method="html" omit-xml-declaration="yes"/>

  <xsl:variable name="theData" select="/document/permission"/>

  <xsl:template match="/document">
    <xsl:variable name="grpcount"  select="count($theData/grp)"/>
    <xsl:call-template name="makeGroupList">
      <xsl:with-param name="groupSize" select="$grpcount"/>
    </xsl:call-template>
  </xsl:template>

  <xsl:template name="makeGroupList">
    <xsl:param name="groupSize"/>
    <select name="selectName" size="{$groupSize}" multiple="true">
      <xsl:apply-templates select="$theData/grp">
        <xsl:sort select="@name"/>
      </xsl:apply-templates>
    </select>
  </xsl:template>

  <xsl:template match="grp">
    <xsl:variable name="gid" select="./@gid"/>
        <option value="{$gid}"><xsl:value-of select="@name"/></option>
  </xsl:template>
</xsl:stylesheet>

Output xalan-j_2_7_0:
<select multiple="true" size="2" name="selectName">
  <option value="101">group1</option>
  <option value="101">group1</option>
  <option value="102">group2</option>
  <option value="102">group2</option>
</select>

However, the output from j_2_6_0 is as expected:

Output xalan-j_2_6_0:
<select multiple="true" size="2" name="selectName">
  <option value="101">group1</option>
  <option value="102">group2</option>
</select>

If I comment out the grpcount variable definition and pass a param with
a literal value in the call to the makeGroupList template, both versions
of xalan produce the same output.

I'd appreciate any insight into why this is happening.

Regards,
Garrel Renick