Function xml_errorHandler

src/backend/utils/adt/xml.c:1764–1929

* Error handler for libxml errors and warnings */

 * Error handler for libxml errors and warnings
 */
static void
xml_errorHandler(void *data, xmlErrorPtr error)
{
	PgXmlErrorContext *xmlerrcxt = (PgXmlErrorContext *) data;
	xmlParserCtxtPtr ctxt = (xmlParserCtxtPtr) error->ctxt;
	xmlParserInputPtr input = (ctxt != NULL) ? ctxt->input : NULL;
	xmlNodePtr	node = error->node;
	const xmlChar *name = (node != NULL &&
						   node->type == XML_ELEMENT_NODE) ? node->name : NULL;
	int			domain = error->domain;
	int			level = error->level;
	StringInfo	errorBuf;

	/*
	 * Defend against someone passing us a bogus context struct.
	 *
	 * We force a backend exit if this check fails because longjmp'ing out of
	 * libxml would likely render it unsafe to use further.
	 */
	if (xmlerrcxt->magic != ERRCXT_MAGIC)
		elog(FATAL, "xml_errorHandler called with invalid PgXmlErrorContext");

	/*----------
	 * Older libxml versions report some errors differently.
	 * First, some errors were previously reported as coming from the parser
	 * domain but are now reported as coming from the namespace domain.
	 * Second, some warnings were upgraded to errors.
	 * We attempt to compensate for that here.
	 *----------
	 */
	switch (error->code)
	{
		case XML_WAR_NS_URI:
			level = XML_ERR_ERROR;
			domain = XML_FROM_NAMESPACE;
			break;

		case XML_ERR_NS_DECL_ERROR:
		case XML_WAR_NS_URI_RELATIVE:
		case XML_WAR_NS_COLUMN:
		case XML_NS_ERR_XML_NAMESPACE:
		case XML_NS_ERR_UNDEFINED_NAMESPACE:
		case XML_NS_ERR_QNAME:
		case XML_NS_ERR_ATTRIBUTE_REDEFINED:
		case XML_NS_ERR_EMPTY:
			domain = XML_FROM_NAMESPACE;
			break;
	}

	/* Decide whether to act on the error or not */
	switch (domain)
	{
		case XML_FROM_PARSER:
		case XML_FROM_NONE:
		case XML_FROM_MEMORY:
		case XML_FROM_IO:

			/*