<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:d="http://www.daisy.org/ns/pipeline/data" version="2.0" exclude-result-prefixes="#all">
<xsl:variable name="spine" select="collection()[2]"/>
<xsl:template match="/*">
<xsl:copy>
<xsl:attribute name="xml:base" select="base-uri(.)"/>
<xsl:for-each select="d:file">
<xsl:copy>
<xsl:copy-of select="@*"/>
<xsl:variable name="href" select="@href"/>
<xsl:if test="$spine/d:file[following-sibling::*][@href=$href]">
<xsl:variable name="next-spine-item" select="$spine/d:file[@href=$href]/following-sibling::*[1]"/>
<xsl:attribute name="fallback" select="//d:file[@href=$next-spine-item/@href]/@id"/>
</xsl:if>
</xsl:copy>
</xsl:for-each>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>