null pointer exception in Saxon

I'm using the extension functions in Saxon to integrate a Java Hashtable
into a stylesheet, but get a null point exception when testing a null value.
The stylesheet is setup as follows:

<xsl:stylesheet
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:hashtable="/java.util.Hashtable"
    xmlns:saxon="http://icl.com/saxon"
    extension-element-prefix="saxon"
    version="1.0" >

   <xsl:variable name="lookup" select="hashtable:new()"/>

in a template, it test this:

      <xsl:if test="hashtable:get($lookup, @name)">

But, if the hashtable key is not present in the hashtable, Saxon throws a
null pointer exception.  I would expect the expression in the xsl:if
statement to return false.  In any case, the null should be caught.  (I'm
using Saxon version 5.3.2).

Dave Carlson


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