Re: Add XMLNamespaces to XMLElement

The following review has been posted through the commitfest application:
make installcheck-world: not tested
Implements feature: not tested
Spec compliant: not tested
Documentation: not tested

Hi Pavel,

I have tested this patch, and it proves to be highly useful when handling XMLNAMESPACES() with both DEFAULT and NO DEFAULT options. The following test cases confirm its correctness:

SELECT xmlelement(
NAME "foo",
XMLNAMESPACES('http://x.y' AS xy, 'http://a.b' AS ab, DEFAULT 'http://d.e'),
xmlelement(NAME "foot",
xmlelement(NAME "xy:shoe"),
xmlelement(NAME "ab:lace")
)
);

SELECT xmlelement(
NAME "foo",
XMLNAMESPACES('http://x.y' AS xy, 'http://a.b' AS ab, NO DEFAULT),
xmlelement(NAME "foot",
xmlelement(NAME "xy:shoe"),
xmlelement(NAME "ab:lace")
)
);
Additionally, I verified that the patch correctly supports multiple namespaces when using both DEFAULT and NO DEFAULT, ensuring expected behavior across different use cases.

Great work on this improvement!