xmlnode: lack of namespace_map and prefixes in parsed xml

Wed Nov 26 10:10:17 EST 2008

Hi,

I'm writing a WS-Notification consumer for SOAP messages transported via XMPP. I'm using 
the "jabber-receiving-xmlnode" signal to capture the messages. However, the WS-NT 
specification relies heavily on XML namespaces, prefixes and scoping.

It seems that pidgin's XML DOM implementation is borked. For example, take this XMPP-SOAP-
Notify message received over the wire:
 <message to='dest' id='528493536683'
from='source'>
  <SOAP-ENV:Envelope xmlns:SOAP-ENV='http://schemas.xmlsoap.org/soap/envelope/'>

    <SOAP-ENV:Header>
      <wsa5:MessageID xmlns:wsa5='http://www.w3.org/2005/08/addressing'>
      1234</wsa5:MessageID>
      <wsa5:From xmlns:wsa5='http://www.w3.org/2005/08/addressing'>
        <wsa5:Address>source</wsa5:Address>
      </wsa5:From>
      <wsa5:To xmlns:wsa5='http://www.w3.org/2005/08/addressing'
      SOAP-ENV:mustUnderstand='1'>dest</wsa5:To>
      <wsa5:Action xmlns:wsa5='http://www.w3.org/2005/08/addressing'
      SOAP-ENV:mustUnderstand='1'>
      http://docs.oasis-open.org/wsn/bw-2/NotificationConsumer/Notify</wsa5:Action>
    </SOAP-ENV:Header>
    <SOAP-ENV:Body>
      <wsnt:Notify xmlns:wsnt='http://docs.oasis-open.org/wsn/b-2'>
        <wsnt:NotificationMessage>
          <wsnt:Topic Dialect='http://docs.oasis-open.org/wsn/t-1/TopicExpression/Full'>
            <TopicExpression xmlns='http://docs.oasis-open.org/wsn/b-2'
            Dialect='http://docs.oasis-open.org/wsn/t-1/TopicExpression/Full'
            xmlns:tns='urn:fedstage:fedcomputing:notification-topic:1.0'
            tns:someargument='somevalue'>
            tns:job/control/resumed</TopicExpression>
          </wsnt:Topic>
          <wsnt:Message>SampleNotification</wsnt:Message>
        </wsnt:NotificationMessage>
      </wsnt:Notify>
    </SOAP-ENV:Body>
  </SOAP-ENV:Envelope>
</message>

Now, take a look at what XMPP console spat out:

<message to='dest' id='528493536683' from='source'>
	<Envelope xmlns='http://schemas.xmlsoap.org/soap/envelope/'>
		<Header>
			<MessageID xmlns='http://www.w3.org/2005/08/addressing'>1234</MessageID>
			<From xmlns='http://www.w3.org/2005/08/addressing'>
				<Address>source</Address>
			</From>
			<To xmlns='http://www.w3.org/2005/08/addressing' mustUnderstand='1'>dest</To>
			<Action xmlns='http://www.w3.org/2005/08/addressing' 
mustUnderstand='1'>http://docs.oasis-open.org/wsn/bw-2/NotificationConsumer/Notify</Action>
		</Header>
		<Body>
			<Notify xmlns='http://docs.oasis-open.org/wsn/b-2'>
				<NotificationMessage>
					<Topic Dialect='http://docs.oasis-open.org/wsn/t-1/TopicExpression/Full'>						
					<TopicExpression Dialect='http://docs.oasis-open.org/wsn/t-1/TopicExpression/Full' 
someargument='somevalue'>tns:job/control/resumed</TopicExpression>

					</Topic>
					<Message>SampleNotification</Message>
				</NotificationMessage>
			</Notify>
		</Body>
	</Envelope>
</message>

What's working:
xmlnode contains the correct xmlns for the XMLNODE_TYPE_TAG nodes (for example, <Envelope> 
has a correct namespace of 'http://schemas.xmlsoap.org/soap/envelope/'). The inheritance 
of namespaces is correct, for example NotificationMessage has xmlns set to the same value 
as Notify.

What's not working:
1. prefixes don't make it into xmlnode structures despite the fact that they should 
according to line 585 of xmlnode.c it happens both for tags and attribs
2. xmlns information for XMLNODE_TYPE_ATTRIB nodes is missing. Take for example the 
tns:someargument='somevalue' attribute of TopicExpression. It should have it's xmlns set 
to 'urn:fedstage:fedcomputing:notification-topic:1.0', but instead NULL is there.
3. Nodes containing declarations of namespace maps do not retain them. Take for example:
<TopicExpression xmlns='http://docs.oasis-open.org/wsn/b-2'
            Dialect='http://docs.oasis-open.org/wsn/t-1/TopicExpression/Full'
            xmlns:tns='urn:fedstage:fedcomputing:notification-topic:1.0'
            tns:someargument='somevalue'>
turned into:
<TopicExpression Dialect='http://docs.oasis-open.org/wsn/t-1/TopicExpression/Full' 
someargument='somevalue'>
Despite the fact that in lines 587-597 of xmlnode.c namespace map are stored inside the 
xmlnode structure.

All these symptoms are related to xmlnode's transported over the jabber-receiving-xmlnode 
signal. Maybe some of this information get's stripped out along the way?

Maybe it's a problem with libxml2, maybe it's a problem with pidgin's xml dom. Maybe 
theres a special switch/define/magic flag which turns that parsing on I don't know of? I've 
got pidgin 2.5.2 and libxml2 2.6.32. Could anyone please help me?

Michal