Saxon

This change in behaviour is probably caused by the fix to bug #4666. I'll need to read the spec carefully to decide which is correct.

FWIW, 10.x worked in its way even before fixing #4666:

$ java -jar SaxonHE10-1J/saxon-he-10.1.jar -it -xsl:test.xsl
<?xml version="1.0" encoding="UTF-8"?>
<description xmlns="x">
   <x:scenario xmlns:x="x">
      <e/>
   </x:scenario>
</description>
$ java -jar SaxonHE10-0J/saxon-he-10.0.jar -it -xsl:test.xsl
<?xml version="1.0" encoding="UTF-8"?>
<description xmlns="x">
   <x:scenario xmlns:x="x">
      <e/>
   </x:scenario>
</description>

I think the 9.9 results are correct.

The <e/> element, under the rules for namespaces on literal result elements, has a single namespace node, x = "x".

The <x:scenario/> element, by the same rules, also has a single namespace node, x = "x". Namespace inheritance is on for the construction of this element, but this does not cause any namespaces to be inherited by <e/>, because it already has all the relevant namespaces.

The <description> element, by the rules for xsl:element, including the namespace fixup rules, has a single namespace node, # = "x", where # represents the null prefix. Namespace inheritance is off, so this namespace is not inherited by the (copied) <x:scenario/> element.

During serialization, a namespace undeclaration should be added to the <x:scenario/> element because its parent has a namespace node for the default namespace, and the <x:scenario/> element does not.

It doesn't seem to have anything to do with bug #4666 after all.

The NamespaceMaps that find their way through to the NamespaceDifferencer (on the serialization pipeline) are correct. The NamespaceDifferencer is making a conscious decision to add a namespace undeclaration for the default namespace only if the (child) element itself is in the default namespace.

I can't see any logic for this decision, and changing it doesn't appear to cause any tests to fail.

Adding the new test case as namespace-0913 in the XSLT3 test suite.

Coming back to this, the test isn't failing even though the patch hasn't been applied and the result appear incorrect. I think that this is because the test suite driver isn't taking account of the namespace undeclaration xmlns="" when evaluating the assert-xml assertion. May need to use more explicit assertions (or improve the assert-xml logic).

I've changed the test to force serialization of the result tree, and to test the serialized output, and it now fails (as expected). This makes sense, because the NamespaceDifferencer is invoked only when we're performing serialization (or creating DOM trees, etc) - it's not needed if the result tree uses the XDM namespace model.

This also confirms that the patch to NamespaceDifferencer works.

Bug fix applied in the Saxon 10.3 maintenance release