CLONE - Streambuffer cannot parse namespaces presented in the SOAP envelope level

We're using the below code snippet to parse SOAP header:

private ServiceContext getDeltaContext (SOAPMessageContext context)

{ Object[] jaxbServiceContext = context.getHeaders(new QName(DFS_CONTEXT_NAMESPACE, "ServiceContext"), SERVICE_CONTEXT_JAXB_CONTEXT, false); ... }

The above code will finally depend on streambuffer to parse the SOAP message. However, we hit the below exception when parsing the attached SOAP message (note that the namespaces are in the envelope level):

Caused by: javax.xml.bind.JAXBException

* with linked exception:
[java.lang.IllegalArgumentException: prefix tns is not bound to a namespace]
at com.sun.xml.ws.message.AbstractHeaderImpl.readAsJAXB(AbstractHeaderImpl.java:81)
at com.sun.xml.ws.handler.SOAPMessageContextImpl.getHeaders(SOAPMessageContextImpl.java:127)
... 34 more
Caused by: java.lang.IllegalArgumentException: prefix tns is not bound to a namespace
at com.sun.xml.bind.DatatypeConverterImpl._parseQName(DatatypeConverterImpl.java:341)
at com.sun.xml.bind.v2.runtime.unmarshaller.XsiTypeLoader.parseXsiType(XsiTypeLoader.java:89)
at com.sun.xml.bind.v2.runtime.unmarshaller.XsiTypeLoader.startElement(XsiTypeLoader.java:67)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext._startElement(UnmarshallingContext.java:481)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.startElement(UnmarshallingContext.java:459)
at com.sun.xml.bind.v2.runtime.unmarshaller.InterningXmlVisitor.startElement(InterningXmlVisitor.java:71)
at com.sun.xml.bind.v2.runtime.unmarshaller.StAXStreamConnector.handleStartElement(StAXStreamConnector.java:242)
at com.sun.xml.bind.v2.runtime.unmarshaller.StAXStreamConnector.bridge(StAXStreamConnector.java:176)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:360)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:332)
at com.sun.xml.ws.message.AbstractHeaderImpl.readAsJAXB(AbstractHeaderImpl.java:79)
... 35 more

After initial investigation, we found this should be caused by a streambuffer bug. If we update the implementation of com.sun.xml.stream.buffer.stax.StreamReaderBufferProcessor.setXMLStreamBuffer(XMLStreamBuffer buffer) like below, the issue can be resolved:
public void setXMLStreamBuffer(XMLStreamBuffer buffer) throws XMLStreamException {
setBuffer(buffer,buffer.isFragment());

_completionState = PARSING;
_namespaceAIIsEnd = buffer.getInscopeNamespaces().size();
Set> entries = buffer.getInscopeNamespaces().entrySet();
Iterator> it = entries.iterator();
int i = 0;
while(it.hasNext() && i < _namespaceAIIsEnd)

{ Entry entry = it.next(); _namespaceAIIsPrefix[i] = entry.getKey(); _namespaceAIIsNamespaceName[i] = entry.getValue(); i++; }

_characters = null;
_charSequence = null;
_eventType = START_DOCUMENT;
}

Streambuffer 1.1 also has this bug.

Btw, at first we were using SOAPMessageContext.getMessage().getSOAPHeader()to parse the SOAP header but there is OOM issue with large MTOM message.
#### Environment
NA
#### Affected Versions
[1.5.2]