Test case: Dialog inside dialog can show below the mask

gistfile1.xml

<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"
      xmlns:fr="http://orbeon.org/oxf/xml/form-runner">
    <xhtml:head>
        <xhtml:title>Submitting instance with required and non-relevant node</xhtml:title>
        <xforms:model>
            <xforms:instance>
                <first-name xmlns=""/>
            </xforms:instance>
            <xforms:bind nodeset="." required="true()" relevant="false()"/>
            <xforms:submission id="submission" resource="" method="post" replace="instance"/>
        </xforms:model>
    </xhtml:head>
    <xhtml:body>
        <xforms:trigger>
            <xforms:label>Open dialog 1</xforms:label>
            <xxforms:show dialog="dialog-1" ev:event="DOMActivate"/>
        </xforms:trigger>

        <xxforms:dialog id="dialog-1">
            <xforms:label>Dialog 1</xforms:label>
            <xhtml:p>First dialog</xhtml:p>
            <xforms:trigger>
                <xforms:label>Open dialog 2</xforms:label>
                <xxforms:show dialog="dialog-2" ev:event="DOMActivate"/>
            </xforms:trigger>
            <xxforms:dialog id="dialog-2">
                <xforms:label>Dialog 2</xforms:label>
                <xhtml:p>Second dialog</xhtml:p>
            </xxforms:dialog>
        </xxforms:dialog>
    </xhtml:body>
</xhtml:html>