Investigate xpath urls

[volosied]

This issue was spun off PR jakartaee/tags#172.

We should investigate if any of the following need to change for EE10? Although, I think it's likely safe (and probably best) to leave these as they are.

https://github.com/eclipse-ee4j/jstl-api/blob/2a60c5505d3466c49e8f4ab1e49ef42ec0e5e7a3/impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/JSTLXPathVariableResolver.java#L40-L55

[volosied]

I tested various jstl xml tags (using examples found in the source files here), and I didn't find a scenario where these namespaces were used? I tested on Open Liberty using JSTL 2.0.

Per one comment,
https://github.com/eclipse-ee4j/jstl-api/blob/2a60c5505d3466c49e8f4ab1e49ef42ec0e5e7a3/impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/XPathUtil.java#L69

But I didn't see the namespaces used again when I added scopes to the JSTL variables. I'm add a loss here to understand their purpose here.

Namespaces are set here:
https://github.com/eclipse-ee4j/jstl-api/blob/2a60c5505d3466c49e8f4ab1e49ef42ec0e5e7a3/impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/XPathUtil.java#L198-L200

https://github.com/eclipse-ee4j/jstl-api/blob/2a60c5505d3466c49e8f4ab1e49ef42ec0e5e7a3/impl/src/main/java/org/apache/taglibs/standard/tag/common/xml/JSTLXPathVariableResolver.java#L81-L83

Interestingly, I found that QNames were set with the namespaces in the older 1.1.x implementations:

XPathUtil.java

 public Vector getVariableQNames() {
    this.globalVarSize = 0;
    Vector<QName> variableVector = new Vector();
    Enumeration<String> enum_ = this.pageContext.getAttributeNamesInScope(1);
    while (enum_.hasMoreElements()) {
      String varName = enum_.nextElement();
      QName varQName = new QName("http://java.sun.com/jstl/xpath/page", "pageScope", varName);
      variableVector.addElement(varQName);
      this.globalVarSize++;
      variableVector.addElement(new QName(null, varName));
      this.globalVarSize++;
    } 

I think it's probably better to leave this issue alone / close it. These namespaces look to be used internally, so if we do need to update them to jakarta instead of java.sun, we should probably be fine.

[volosied]

I don't see any issue with this as is for EE10. We can work on this in at a later date.