Saxon

I have an XSL template that looks like this:

    <xsl:template match="text()[. castable as xs:base64Binary]" as="xs:string">
...
    </xsl:template>

This works fine for things that are castable, but unfortunately leads to an internal error in Saxon if it is not. In my case I have a diacritical character in the string: "is geïnteresseerd"

I've attached a tiny tester that I ran against itself to reproduce.

$ java -jar ~/Development/lib/SaxonPE9-7-0-4J/saxon9pe.jar -xsl:pre-process-xml.xsl pre-process-xml.xsl 
...
java.lang.RuntimeException: Internal error evaluating template rule  at line 24 in module