Issue: Deprecation of the XML2 module 'xml_is_well_formed' function

We need to make extensive use of the 'xml_is_well_formed' function provided
by the XML2 module.

Yet the documentation says that the xml2 module will be deprecated since
"XML syntax checking and XPath queries"
is covered by the XML-related functionality based on the SQL/XML standard in
the core server from PostgreSQL 8.3 onwards.

However, the core function XMLPARSE does not provide equivalent
functionality since when it detects an invalid XML document,
it throws an error rather than returning a truth value (which is what we
need and currently have with the 'xml_is_well_formed' function).

For example:

select xml_is_well_formed('<br></br2>');
xml_is_well_formed
--------------------
f
(1 row)

select XMLPARSE( DOCUMENT '<br></br2>' );
ERROR: invalid XML document
DETAIL: Entity: line 1: parser error : expected '>'
<br></br2>
^
Entity: line 1: parser error : Extra content at the end of the document
<br></br2>
^

Is there some way to use the new, core XML functionality to simply return a
truth value
in the way that we need?.

Thanks,
-- Mike Berrow