<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                version="1.0">

  <xsl:template match="/">
    <foo attr="{{escaped curly brackets}}"/>
  </xsl:template>

</xsl:stylesheet>

The stylesheet above is incorrectly rejected by libxslt-0.9.0. The
expected output is:

<?xml version="1.0"?>
<foo attr="{escaped curly brackets}"/>