Validate in place applied on non-root element produces an invalid xdm instance

[Federico Cavalieri]

If validate-in-place is called on a non-root element the resulting xdm instance can be invalid since it may contain typed nodes as descendant of untyped nodes.

Schema
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
 targetNamespace="http://www.zorba-xquery.org/schema" xmlns="http://www.zorba-xquery.org/schema"
 elementFormDefault="qualified">

 <xs:element name="root" type="rootType"/>

 <xs:complexType name="rootType">
  <xs:sequence>
   <xs:element name="root" type="rootType" minOccurs="0"/>
   <xs:element name="a" type="xs:string"/>
   <xs:element name="b" type="xs:string"/>
   <xs:element name="c" type="xs:string"/>
  </xs:sequence>
  <xs:attribute name="attr" type="xs:string"/>
 </xs:complexType>

</xs:schema>

Query
import module namespace schema = "http://www.zorba-xquery.com/modules/schema";
import module namespace doc = "http://www.zorba-xquery.com/modules/store/dynamic/documents";
import schema namespace d="http://www.zorba-xquery.org/schema" at "val-inplace-err2.xsd";

declare revalidation lax;
declare construction strip;

declare variable $doc2:=<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.zorba-xquery.org/schema">
    <root>
        <a/>
        <b/>
        <c/>
    </root>
    <a/>
    <b/>
    <c/>
</root>;

schema:validate-in-place($doc2/d:root);

(schema:schema-type($doc2), schema:schema-type($doc2/d:root))

Result
xs:untyped rootType