Redefining model group definitions (XSV crash)

Hi,

XSV 2.10 crashes in the following scenario:

redef-group.xsd
---------------
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
	targetNamespace="urn:test:foo"
	xmlns:f="urn:test:foo">

	<xsd:redefine schemaLocation="redef-group.inc.xsd">
		<xsd:group name="thisGroup">
			<xsd:sequence>
				<xsd:group ref="f:otherGroup"/>
			</xsd:sequence>
		</xsd:group>
	</xsd:redefine>	

	<xsd:group name="otherGroup">
		<xsd:sequence>
			<xsd:group ref="f:thisGroup"/>
		</xsd:sequence>
	</xsd:group>

	<xsd:element name="foo">
		<xsd:complexType>
			<xsd:group ref="f:thisGroup"/>
		</xsd:complexType>
	</xsd:element>

</xsd:schema>

redef-group.inc.xsd
-------------------
<xsd:schema
	xmlns:xsd="http://www.w3.org/2001/XMLSchema"
	targetNamespace="urn:test:foo">

	<xsd:group name="thisGroup">
		<xsd:sequence>
			<xsd:element name="bar" type="xsd:string"/>
		</xsd:sequence>
	</xsd:group>

</xsd:schema>

redef-group.xml
---------------
<foo xmlns="urn:test:foo"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="urn:test:foo redef-group.xsd"/>

XSV reports:

<xsv xmlns="http://www.w3.org/2000/05/xsv" crash="true"
     docElt="{urn:test:foo}foo" instanceAssessed="true"
instanceErrors="0"
     rootType="[Anonymous]" schemaErrors="0"
     schemaLocs="urn:test:foo -> redef-group.xsd"
     target="file:///p:/libxml2-lab/tests/2005-09-14/redef-group.xml"
     validation="strict" version="XSV 2.10-1 of 2005/04/22 13:10:49">
...
<bug>validator crash during validation</bug>

while Xerces-J 2.7.1 reports:

redef-group.xsd:16,34: (Error) mg-props-correct.2: Circular definitions
detected for group 'f:thisGroup'. Recursively following the {term}
values of the particles leads to a particle whose {term} is the group
itself.
redef-group.xsd:7,31: (Error) cos-particle-restrict.a: Derived particle
is empty, and base is not emptiable.
redef-group.xsd:7,31: (Error) src-redefine.6.2.2: Group 'thisGroup' does
not properly restrict the group it redefines; constraint violated:
'cos-particle-restrict.a'.

Regards,

Kasimier