[jdom-interest] Namespace declaration "gets lost"

[Laurent Bihanic]

Hi,

I had a quick look at SAXHandler code and it seems the bug lay in the use of 
List.removeAll(Collection) in endElement (see line 
availableNamespaces.removeAll(addl);).

IMHO, the scenario is the following: After the second declaration, your 
namespace appears twice in the list of available namespaces (good) and also as 
an additional namespace for the current element (good too). When processing 
the endElement event, SAXHandler removes all the additional namespaces of the 
"ended" element from the list of available namespaces using List.removeAll. 
This method removes *all* occurrences of the objects contained in the 
collection passed as argument. Hence the two namespace declaration are removed 
(bad!).
Later on, when encountering the "returnvalue" attribute, SAXHandler fails to 
resolve the namespace and uses NO_NAMESPACE instead (bad too!) (see method 
getNamespace).

Questions :
1. Why does endElement() remove the additional namespaces from the list of 
available namespaces ? SAX dedicates this task to endPrefixMapping and 
SAXHandler.endPrefixMapping does it perfectly.
2. Why does getNamespace silently absorb attempts to match unknown prefixes? 
This would be acceptable when the prefix does not reference a namespace but 
this case is not handled by this method (see test on 
attQName.equals(attLocalName) in startElement).

Stefan, as a temporary fix, you should delete/comment out the following lines 
from SAXHandler.endElement() and rebuild jdom.jar:
             // Remove the namespaces that this element makes available
             List addl = element.getAdditionalNamespaces();
             if (addl.size() > 0) {
                 availableNamespaces.removeAll(addl);

This will let the underlying XML parser decide when a namespace prefix goes 
out of scope rather than having JDOM do it.

Hope this helps,

Laurent


Liebig, Stefan wrote:
> Hi,
> 
> When parsing the following XML document with JDOM_beta8 and trying to
> "analyze" it´s
> content, it seems that after the second (redundant but legal, or?) "ino"
> namesspace
> decl. JDOM gets confused.
> 
> <?xml version="1.0" encoding="utf-8" ?>
> <ino:response xmlns:ino="http://namespaces.softwareag.com/tamino/response2"
> xmlns:xql="http://metalab.unc.edu/xql/">
> 	<xql:query>
> 		testUpdate_sli[@ino:id=1]
> 	</xql:query>
> 	<ino:message ino:returnvalue="0">
> 		<ino:messageline>
> 			XQL Request processing
> 		</ino:messageline>
> 	</ino:message>
> 	<xql:result>
> 		<testUpdate_sli ino:id="1"
> xmlns:ino="http://namespaces.softwareag.com/tamino/response2">
> 			DOC: -1
> 		</testUpdate_sli>
> 	</xql:result>
> 	<ino:message ino:returnvalue="0">
> 		<ino:messageline>
> 			XQL Request processed
> 		</ino:messageline>
> 	</ino:message>
> </ino:response>
> 
> When running the attached JunitTest the output shows the following:
> 
> Next message tag
> AttributesList:[[Attribute: ino:returnvalue="0"]]
> Attribute.name:returnvalue
> Attribute.value:0
> Attribute.getNS:[Namespace: prefix "ino" is mapped to URI
> "http://namespaces.softwareag.com/tamino/response2"]
> ReturnValue:0
> text:			XQL Request processing		
> Next message tag
> AttributesList:[[Attribute: returnvalue="0"]]
> Attribute.name:returnvalue
> Attribute.value:0
> Attribute.getNS:[Namespace: prefix "" is mapped to URI ""]
> ReturnValue:null
> text:			XQL Request processed		
> 
> As you can see the second message element has "lost" it´s namespace
> and so the "ino:returnvalue" can not be evaluated correctly.
> BTW, with Xerces/DOM it is evaluated correctly.
> 
> Stefan