DO NOT REPLY [Bug 15835] New: - get a nullpointerexception during transformation

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=15835

get a nullpointerexception during transformation

           Summary: get a nullpointerexception during transformation
           Product: XalanJ2
           Version: 2.4
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: Normal
          Priority: Other
         Component: Xalan
        AssignedTo: [EMAIL PROTECTED]
        ReportedBy: [EMAIL PROTECTED]


try to apply:
<?xml version="1.0" encoding="UTF-8" ?>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>

        <xsl:template match="/">
                <xsl:apply-templates select="//nota"/>
        </xsl:template>

        <xsl:template match="nota">
                <xsl:variable name="o" select="object"/>
                <xsl:variable name="mm" 
select="//materia_ptr[preceding-sibling::name=$o]"/>

                <xsl:value-of select="//interface[preceding-sibling::name=$o]"/>
                <!-- la stampa della materia va in NullPointerException con xalan240 
-->
                <xsl:if test="$mm != ''">
(<xsl:value-of select="$mm"/>)
(<xsl:value-of select="/*/materia_header[name='endo_specifici']/interface"/>)
(<xsl:value-of select="/*/materia_header[name=$mm]/interface"/>)
                </xsl:if>
                <xsl:if test="section!='vt'">
                        /
                        <xsl:value-of select="substring(section,3)"/>
                </xsl:if>
        </xsl:template>

</xsl:stylesheet>

to:
<?xml version="1.0" encoding="UTF-8"?>
<xpathresult_notevt><collection>materie</collection><object>distributori_di_carburanti</object><section>vt</section><nota><name>231ef9c375d135a0000000f154966db6</name><collection>materie</collection><object>distributori_di_carburanti</object><section>vt</section><login>rdp</login><timestamp
time="1036510267592">Nov 5, 2002 3:31:07
PM</timestamp><annotazione>dd</annotazione></nota><materia_header><name>distributori_di_carburanti</name><interface>DISTRIBUTORI
DI
CARBURANTI</interface><materia_ptr>endo_specifici</materia_ptr><area_ptr>area_misc</area_ptr></materia_header><materia_header><name>endo_specifici</name><interface>Endoprocedimenti
Specifici</interface></materia_header></xpathresult_notevt>