Repro case for https://github.com/orbeon/orbeon-forms/issues/245

gistfile1.html

<xhtml:html xmlns:xhtml="http://www.w3.org/1999/xhtml"
      xmlns:xforms="http://www.w3.org/2002/xforms"
      xmlns:xxforms="http://orbeon.org/oxf/xml/xforms"
      xmlns:ev="http://www.w3.org/2001/xml-events"
      xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xhtml:head>
        <xforms:model>
            <xforms:instance>
                <value/>
            </xforms:instance>
            <xforms:bind ref="." type="xs:date" readonly="true()"/>
        </xforms:model>
    </xhtml:head>
    <xhtml:body>
        <xforms:input ref="."/>
    </xhtml:body>
</xhtml:html>