Walking a tree

<node>
  <node name="node1">
    <leaf name="leaf1"/>
    <leaf name="leaf2"/>
  </node>
  <node name="node2">
    <node name="node22">
      <leaf name="leaf221"/>
      <leaf name="leaf222"/>
    </node>
    <node name="node23">
      <leaf name="leaf231"/>
      <leaf name="leaf232"/>
    </node>
    <node name="node24">
      <leaf name="leaf241"/>
      <leaf name="leaf242"/>
    </node>
  </node>
</node>

  <xsl:template name="pageNav">
    <xsl:param name="targetNode"/>
    <xsl:param name="currentNode"/>
      <xsl:for-each select="$currentNode/node|$currentNode/leaf">
	... lots of presentation code ...

            <!-- I guess it's this test that should be modified -->
              <xsl:if test=". = $targetNode/ancestor-or-self::node">
                <xsl:call-template name="pageNav">
                  <xsl:with-param name="targetNode" select="$targetNode"/>
                  <xsl:with-param name="currentNode" select="."/>
                </xsl:call-template>
              </xsl:if>
      </xsl:for-each>
  </xsl:template>