Default tunnel parameters.

Hello,

Can you please estimate the value reported in xsl:message in a
following stylesheet?
Saxon 9.1 reports value 2.
My expectation is 1.
If 2
is correct output then can you please justify it.

<xsl:stylesheet
version="2.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:p="http://www.nesterovsky-bros.com">

  <xsl:template match="/">
<xsl:call-template name="p:test"/>
  </xsl:template>

  <xsl:template
name="p:test">
    <xsl:param name="index" as="xs:integer" select="1"/>
<xsl:param name="value" tunnel="yes" as="xs:integer" select="$index"/>
<xsl:choose>
      <xsl:when test="$index lt 2">
        <xsl:call-template
name="p:test">
          <xsl:with-param name="index" select="$index + 1"/>
</xsl:call-template>
      </xsl:when>
      <xsl:otherwise>
<xsl:message select="$value"/>
      </xsl:otherwise>
    </xsl:choose>
</xsl:template>

</xsl:stylesheet>

P.S. I'm asking this question here as
I have recieved no answer at
http://sourceforge.net/forum/message.php?msg_id=5193309.

Thanks.
--
Vladimir Nesterovsky
http://www.nesterovsky-bros.com