From ec693a3f304cf91c717c0fe07abcd4185952fde5 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 18 Sep 2023 14:27:47 -0400 Subject: Don't crash if cursor_to_xmlschema is used on a non-data-returning Portal. cursor_to_xmlschema() assumed that any Portal must have a tupDesc, which is not so. Add a defensive check. It's plausible that this mistake occurred because of the rather poorly chosen name of the lookup function SPI_cursor_find(), which in such cases is returning something that isn't very much like a cursor. Add some documentation to try to forestall future errors of the same ilk. Report and patch by Boyu Yang (docs changes by me). Back-patch to all supported branches. Discussion: https://postgr.es/m/dd343010-c637-434c-a8cb-418f53bda3b8.yangboyu.yby@alibaba-inc.com --- src/backend/utils/adt/xml.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'src/backend/utils/adt/xml.c') diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c index 866d0d649a4..2300c7ebf34 100644 --- a/src/backend/utils/adt/xml.c +++ b/src/backend/utils/adt/xml.c @@ -3012,6 +3012,10 @@ cursor_to_xmlschema(PG_FUNCTION_ARGS) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_CURSOR), errmsg("cursor \"%s\" does not exist", name))); + if (portal->tupDesc == NULL) + ereport(ERROR, + (errcode(ERRCODE_INVALID_CURSOR_STATE), + errmsg("portal \"%s\" does not return tuples", name))); xmlschema = _SPI_strdup(map_sql_table_to_xmlschema(portal->tupDesc, InvalidOid, nulls, -- cgit v1.2.3