Fix nested error handling in PG_FINALLY

petere · petere · commit 581a55889ba7 · 2019-11-07T09:56:47.000+01:00
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
@@ -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
@@ -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)
 
 /*

Original file line number	Diff line number	Diff line change
`@@ -3868,7 +3868,7 @@ xml_xmlnodetoxmltype(xmlNodePtr cur, PgXmlErrorContext *xmlerrcxt)`
`3868`	`3868`
`3869`	`3869`	`result = xmlBuffer_to_xmltype(buf);`
`3870`	`3870`	`}`
`3871`		`- PG_FINALLY()`
	`3871`	`+ PG_FINALLY();`
`3872`	`3872`	`{`
`3873`	`3873`	`if (nodefree)`
`3874`	`3874`	`nodefree(cur_copy);`