"Cannot convert zero-length string to an integer" error in dita2fo_tableelements.xsl; Line#: 1164; Column#: 18

[ToshihikoMakita]

This error occurs in the following code:

    <!-- namest,nameend -->
    <xsl:if test="exists($prmEntry/@namest) and exists($prmEntry/@nameend)">
        <xsl:variable name="startpos" as="xs:integer" select="xs:integer(string($prmColSpec[string(@ahf:column-name) eq string($prmEntry/@namest)]/@column-number))"/>
        <xsl:variable name="endpos"   as="xs:integer" select="xs:integer(string($prmColSpec[string(@ahf:column-name) eq string($prmEntry/@nameend)]/@column-number))"/>
        <xsl:variable name="spancolumns" as="xs:integer" select="$endpos - $startpos + 1"/>
        <xsl:attribute name="number-columns-spanned" select="string($spancolumns)"/>
    </xsl:if>

Should be protected by using "castable as" XPath expression.