From: Peter Eisentraut <peter@eisentraut.org>
Date: Thu, 7 Nov 2019 08:54:09 +0000 (+0100)
Subject: Fix nested error handling in PG_FINALLY
X-Git-Tag: REL_13_BETA1~1219
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=581a55889ba7f76dd87a270e37e5137f684bfdb7;p=thirdparty%2Fpostgresql.git

Fix nested error handling in PG_FINALLY

We need to pop the error stack before running the user-supplied
PG_FINALLY code.  Otherwise an error in the cleanup code would end up
at the same sigsetjmp() invocation and result in an infinite error
handling loop.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com
---

diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 3bc17164312..1ec16f49b29 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -3868,7 +3868,7 @@ xml_xmlnodetoxmltype(xmlNodePtr cur, PgXmlErrorContext *xmlerrcxt)
 
 			result = xmlBuffer_to_xmltype(buf);
 		}
-		PG_FINALLY()
+		PG_FINALLY();
 		{
 			if (nodefree)
 				nodefree(cur_copy);
diff --git a/src/include/utils/elog.h b/src/include/utils/elog.h
index 853c2e0709e..47412a831f0 100644
--- a/src/include/utils/elog.h
+++ b/src/include/utils/elog.h
@@ -338,14 +338,16 @@ extern PGDLLIMPORT ErrorContextCallback *error_context_stack;
 		} \
 		else \
 			_do_rethrow = true; \
-		{
+		{ \
+			PG_exception_stack = _save_exception_stack; \
+			error_context_stack = _save_context_stack
 
 #define PG_END_TRY()  \
 		} \
-		PG_exception_stack = _save_exception_stack; \
-		error_context_stack = _save_context_stack; \
 		if (_do_rethrow) \
 				PG_RE_THROW(); \
+		PG_exception_stack = _save_exception_stack; \
+		error_context_stack = _save_context_stack; \
 	} while (0)
 
 /*