How to convert a negative decimal into hexadecimal using xslt 1 - xslt

Question

I would like to convert negative and positive decimal into hexadecimal using xslt 1.0.
There's already a topic related to this question here but the answer is given using xslt 2.0.
I tried to reproduce the template using xslt 1.0 but it always returns an empty value.
<xsl:template name="convertDecToHex">
<xsl:param name="pInt" />
<xsl:variable name="vMinusOneHex64"><xsl:number>18446744073709551615</xsl:number></xsl:variable>
<xsl:variable name="vCompl">
<xsl:choose>
<xsl:when test="$pInt > 0">
<xsl:value-of select="$pInt" />
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="$vMinusOneHex64 + $pInt + 1" />
</xsl:otherwise>
</xsl:choose>
</xsl:variable>
<xsl:choose>
<xsl:when test="vCompl = 0">
<xsl:text>0</xsl:text>
</xsl:when>
<xsl:otherwise>
<xsl:choose>
<xsl:when test="vCompl > 16">
<xsl:variable name="result">
<xsl:call-template name="convertDecToHex">
<xsl:with-param name="pInt" select="$vCompl div 16" />
</xsl:call-template>
</xsl:variable>
<xsl:value-of select="concat($result,substring('0123456789ABCDEF',($vCompl div 16) + 1,1))" />
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="concat('',substring('0123456789ABCDEF',($vCompl div 16) + 1,1))" />
</xsl:otherwise>
</xsl:choose>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
Could you help me making it work?

Answer 1

To convert a decimal number to 32-bit signed hexadecimal in pure XSLT 1.0:
<xsl:template name="dec2signedhex">
<xsl:param name="decimal"/>
<xsl:variable name="n">
<xsl:choose>
<xsl:when test="$decimal < 0">
<xsl:value-of select="$decimal + 4294967296"/>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="$decimal"/>
</xsl:otherwise>
</xsl:choose>
</xsl:variable>
<xsl:variable name="q" select="floor($n div 16)"/>
<xsl:if test="$q">
<xsl:call-template name="dec2signedhex">
<xsl:with-param name="decimal" select="$q"/>
</xsl:call-template>
</xsl:if>
<xsl:value-of select="substring('0123456789ABCDEF', $n mod 16 + 1, 1)"/>
</xsl:template>