XSLT value-of (within template called with param) seems to work or stop working, depending on other children of the node passed as param

Question

I have the following structure(s) in my xml:

<modelData>
   <metadata>
      <approverDetails instanceId="0">
            <userId/>
            <userIdNamespace/>
            <fullName>James John Johnson<fullName/>
      </approverDetails>
      <reviewerDetails instanceId="0">
            <userId/>
            <userIdNamespace/>
            <fullName>Johanna Jameson<fullName/>
      </reviewerDetails>
   </metadata>
</modelData>

and the xslt to go with it:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

   <xsl:template name="userdetailinfo">
        <xsl:param name="personDetails" />

        <xsl:variable name="fullNameVar">
             (<xsl:value-of select="$personDetails/fullName" />)
        </xsl:variable>

        <xsl:if test="$fullNameVar!= ''">
            <xsl:value-of select="$fullNameVar"/>
        </xsl:if>

    </xsl:template>


<xsl:template match="/">
Report Approver: 
   <xsl:call-template name="userdetailinfo">
      <xsl:with-param name="personDetails" select="/modelData/metadata/approverDetails"/>
   </xsl:call-template>
</xsl:template>

</xsl:stylesheet>

This, as expected, produces the following output:

Report Approver: (James John Johnson)

However, when I modify the xml to add a value to the userIdNamespace tag, like so (line 5):

<modelData>
   <metadata>
      <approverDetails instanceId="0">
            <userId/>
            <userIdNamespace>johns-user-id-namespace<userIdNamespace/>
            <fullName>James John Johnson<fullName/>
      </approverDetails>
      <reviewerDetails instanceId="0">
            <userId/>
            <userIdNamespace/>
            <fullName>Johanna Jameson<fullName/>
      </reviewerDetails>
   </metadata>
</modelData>

This should have no influence on the output, I was expecting identical output as before. Instead, I am getting this:

Report Approver: ()

Clearly, I am misunderstanding how XSLT works, but I couldn't find any useful answers anywhere. Anyone care to help me figure out what I am doing wrong?

Answer 1

The problem was due to wrong closing tags, <closed><closed/> instead of <closed></closed>.