1 files changed, 45 insertions, 0 deletions
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index 0cc77190dc4..8f0886f2ff6 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -6853,6 +6853,51 @@ SELECT * FROM ft1 ORDER BY c6 ASC NULLS FIRST, c1 OFFSET 15 LIMIT 10;
    40 |  42 | 00040_trig_update | Tue Feb 10 00:00:00 1970 PST | Tue Feb 10 00:00:00 1970 | 0    | 0          | foo
 (10 rows)
 
+-- Test ReScan code path that recreates the cursor even when no parameters
+-- change (bug #17889)
+CREATE TABLE loct1 (c1 int);
+CREATE TABLE loct2 (c1 int, c2 text);
+INSERT INTO loct1 VALUES (1001);
+INSERT INTO loct1 VALUES (1002);
+INSERT INTO loct2 SELECT id, to_char(id, 'FM0000') FROM generate_series(1, 1000) id;
+INSERT INTO loct2 VALUES (1001, 'foo');
+INSERT INTO loct2 VALUES (1002, 'bar');
+CREATE FOREIGN TABLE remt2 (c1 int, c2 text) SERVER loopback OPTIONS (table_name 'loct2');
+ANALYZE loct1;
+ANALYZE remt2;
+SET enable_mergejoin TO false;
+SET enable_hashjoin TO false;
+SET enable_material TO false;
+EXPLAIN (VERBOSE, COSTS OFF)
+UPDATE remt2 SET c2 = remt2.c2 || remt2.c2 FROM loct1 WHERE loct1.c1 = remt2.c1 RETURNING remt2.*;
+                                   QUERY PLAN                                   
+--------------------------------------------------------------------------------
+ Update on public.remt2
+   Output: remt2.c1, remt2.c2
+   Remote SQL: UPDATE public.loct2 SET c2 = $2 WHERE ctid = $1 RETURNING c1, c2
+   ->  Nested Loop
+         Output: (remt2.c2 || remt2.c2), remt2.ctid, remt2.*, loct1.ctid
+         Join Filter: (remt2.c1 = loct1.c1)
+         ->  Seq Scan on public.loct1
+               Output: loct1.ctid, loct1.c1
+         ->  Foreign Scan on public.remt2
+               Output: remt2.c2, remt2.ctid, remt2.*, remt2.c1
+               Remote SQL: SELECT c1, c2, ctid FROM public.loct2 FOR UPDATE
+(11 rows)
+
+UPDATE remt2 SET c2 = remt2.c2 || remt2.c2 FROM loct1 WHERE loct1.c1 = remt2.c1 RETURNING remt2.*;
+  c1  |   c2   
+------+--------
+ 1001 | foofoo
+ 1002 | barbar
+(2 rows)
+
+RESET enable_mergejoin;
+RESET enable_hashjoin;
+RESET enable_material;
+DROP FOREIGN TABLE remt2;
+DROP TABLE loct1;
+DROP TABLE loct2;
 -- ===================================================================
 -- test check constraints
 -- ===================================================================