PG_CATCH used without PG_RETHROW

My understanding is that PG_TRY/PG_CATCH doesn't save enough state to
avoid rethrowing errors and if you want to actually continue the
transaction you must use a subtransaction. As a result I was under the
impression it was mandatory to PG_RETHROW as a result.

If that's the case then I think I just came across a bug in
utils/adt/xml.c where there's no PG_RETHROW:

/** Functions for checking well-formed-ness*/

#ifdef USE_LIBXML
static bool
wellformed_xml(text *data, XmlOptionType xmloption_arg)
{
bool result;
volatile xmlDocPtr doc = NULL;

/* We want to catch any exceptions and return false */
PG_TRY();
{
doc = xml_parse(data, xmloption_arg, true, GetDatabaseEncoding());
result = true;
}
PG_CATCH();
{
FlushErrorState();
result = false;
}
PG_END_TRY();

if (doc)
xmlFreeDoc(doc);

return result;
}
#endif

-- 
greg