Back-patch today's memory management fixups in contrib/xml2.

Prior to 8.3, these changes are not critical for compatibility with core
Postgres, since core had no libxml2 calls then.  However there is still
a risk if contrib/xml2 is used along with libxml2 functionality in Perl
or other loadable modules.  So back-patch to all versions.

Also back-patch addition of regression tests.  I'm not sure how many of
the cases are interesting without the interaction with core xml code,
but a silly regression test is still better than none at all.

1 files changed, 10 insertions, 11 deletions

diff --git a/contrib/xml2/xslt_proc.c b/contrib/xml2/xslt_proc.c
index ab0caaa998e..a38ab5a7a87 100644
--- a/contrib/xml2/xslt_proc.c
+++ b/contrib/xml2/xslt_proc.c
@@ -21,22 +21,21 @@
 #include <libxslt/xsltutils.h>
 
 
-/* declarations to come from xpath.c */
+/* externally accessible functions */
 
-extern void elog_error(int level, char *explain, int force);
-extern void pgxml_parser_init();
-extern xmlChar *pgxml_texttoxmlchar(text *textstring);
+Datum		xslt_process(PG_FUNCTION_ARGS);
 
-#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
+/* declarations to come from xpath.c */
+extern void elog_error(const char *explain, bool force);
+extern void pgxml_parser_init(void);
 
 /* local defs */
 static void parse_params(const char **params, text *paramstr);
 
-Datum		xslt_process(PG_FUNCTION_ARGS);
-
-
 #define MAXPARAMS 20			/* must be even, see parse_params() */
 
+#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
+
 
 PG_FUNCTION_INFO_V1(xslt_process);
 
@@ -82,7 +81,7 @@ xslt_process(PG_FUNCTION_ARGS)
 	if (doctree == NULL)
 	{
 		xmlCleanupParser();
-		elog_error(ERROR, "error parsing XML document", 0);
+		elog_error("error parsing XML document", false);
 
 		PG_RETURN_NULL();
 	}
@@ -96,7 +95,7 @@ xslt_process(PG_FUNCTION_ARGS)
 		{
 			xmlFreeDoc(doctree);
 			xmlCleanupParser();
-			elog_error(ERROR, "error parsing stylesheet as XML document", 0);
+			elog_error("error parsing stylesheet as XML document", false);
 			PG_RETURN_NULL();
 		}
 
@@ -111,7 +110,7 @@ xslt_process(PG_FUNCTION_ARGS)
 		xmlFreeDoc(doctree);
 		xsltCleanupGlobals();
 		xmlCleanupParser();
-		elog_error(ERROR, "failed to parse stylesheet", 0);
+		elog_error("failed to parse stylesheet", false);
 		PG_RETURN_NULL();
 	}