Please describe the problem:
The function receives a text node, which is not converted to its string value.



Steps to reproduce:
1. avail-test.xml:
<e>xsl:number</e>
2. avail-test.xsl:
<xsl:stylesheet version="1.0" 	xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/"><xsl:apply-templates/></xsl:template>
<xsl:template match="e">
	<xsl:copy>
		<xsl:value-of select="element-available(.)"/>
	</xsl:copy>
</xsl:template>
</xsl:stylesheet>
3. xsltproc avail-test.xsl avail-test.xml


Actual results:
<?xml version="1.0"?>
<e/>
runtime error: file avail-test.xsl line 14 element value-of
element-available() : invalid arg expecting a string
runtime error: file avail-test.xsl line 14 element value-of
XPath evaluation returned no result.
>Exit code: 10

Expected results:
<?xml version="1.0"?>
<e>true</e>

Does this happen every time?
Yes

Other information:
Same problem for function-available()