[XALANJ-2302] Prefix collision bug during serialization

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Xalan info: PatchAvailable
• Assignee: Unassigned
• Reporter: Brian Minchau
• Reviewer: Yash Talwar
• Created: 21/Jun/06 02:26
• Updated: 17/Oct/06 16:06

Description

During work on xalanj-2219, which Henry Zongaro reviewed, he found a related bug where
an attribute added through manipulation of a DOM would cause a prefix collision.

His testcase was similar to the one in xalanj-2219. First create an element named "p:child" in namespace URI "child".
When serialized this element would look like this:
<p:child xmlns='child' />

Then to this DOM Element, add an attribute named q:attr with value 'val' and have attribute in the namespace 'moo'.
When serialized this element would look like this:
<p:child xlmns='child' q:attr='val' xmlns:q='moo' />

Now to cause the collision have the name of the attribute be 'p:attr'. The prefix p must map to both 'child' and to 'moo'.
The only way out is to NOT use p for one of the prefixes, and to pick a new one that is not mapped, something like this:
<p:child xmlns='child' ns0:attr='val' xmlns:ns0='moo' />

Henry's testcase, much like the one in xalanj-2219 is this:
-------------------------------------------------------------------------------
import java.io.StringReader;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.InputSource;
public class j2219b {
private static final String IDENTITY_XSLT_WITH_INDENT =
"<xsl:stylesheet version='1.0' " +
"xmlns:xsl='http://www.w3.org/1999/XSL/Transform' " +
"xmlns:xalan='http://xml.apache.org/xslt' " +
"exclude-result-prefixes='xalan'>" +
"<xsl:output method='xml' indent='yes' xalan:indent-amount='4'/>" +
"<xsl:template match='@*|node()'>" +
"<xsl:copy>" +
"<xsl:apply-templates select='@*|node()'/>" +
"</xsl:copy>" +
"</xsl:template>" +
"</xsl:stylesheet>";
public static void main(String[] args) throws Exception

{ String data = "<p:root xmlns:p='root'/>"; DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); dbf.setNamespaceAware(true); Document doc = dbf.newDocumentBuilder().parse(new InputSource(new StringReader(data))); Element e = doc.createElementNS("child", "p:child"); e.setAttributeNS("moo", "p:attr", "val"); doc.getDocumentElement().appendChild(e); Transformer t = TransformerFactory.newInstance().newTransformer( new StreamSource(new StringReader(IDENTITY_XSLT_WITH_INDENT))); Source source = new DOMSource(doc); Result result = new StreamResult(System.out); t.transform(source, result); }

}

-------------------------------------------------------------------------------

Now there is a problem. When serialized the same prefix cannot be used

Issue Links

• is related to: XALANJ-2219 Namespace of child element written incorrectly as root namespace
• relates to: XALANJ-2219 Namespace of child element written incorrectly as root namespace