The issue is covered by org.jboss.test.ws.jbws718.JBWS718TestCase on branch 'jbossws-1.0_SchemaBindingMarshaller':

Caused by: java.lang.NullPointerException
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshalCharacters(MarshallerImpl.java:1005)
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshalCharacters(MarshallerImpl.java:1082)
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshalSimpleType(MarshallerImpl.java:477)
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshalElementType(MarshallerImpl.java:421)
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshalElement(MarshallerImpl.java:336)
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshalElementOccurence(MarshallerImpl.java:316)
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshallInternal(MarshallerImpl.java:215)
at org.jboss.xb.binding.sunday.marshalling.MarshallerImpl.marshal(MarshallerImpl.java:173)
at org.jboss.ws.jaxb.JAXBMarshallerImpl.marshal(JAXBMarshallerImpl.java:173)
at org.jboss.ws.jaxrpc.encoding.JAXBSerializer.serialize(JAXBSerializer.java:98)
at org.jboss.ws.soap.SOAPContentElement.getXMLFragment(SOAPContentElement.java:152)