ROW_NUMBER is wrong upon INSERT or UPDATE on Spider table

install soname 'ha_spider';

set spider_same_server_link=1;

CREATE OR REPLACE TABLE t (id INT PRIMARY KEY);

eval CREATE OR REPLACE TABLE spd (id INT PRIMARY KEY) ENGINE=SPIDER COMMENT 'host "127.0.0.1", user "root", password "", port "$MASTER_MYPORT", table "t"';

--error ER_DUP_ENTRY

INSERT INTO spd VALUES (1),(2),(1);

GET DIAGNOSTICS CONDITION 1 @n = ERROR_INDEX;

SELECT @n;

DELETE FROM t;

INSERT INTO spd VALUES (1),(2),(3),(13);

--error ER_DUP_ENTRY

UPDATE spd SET id = id + 10;

GET DIAGNOSTICS CONDITION 1 @n = ERROR_INDEX;

SELECT @n;

INSERT INTO spd VALUES (1),(2),(1);

ERROR 23000: Duplicate entry '1' for key 'PRIMARY'

GET DIAGNOSTICS CONDITION 1 @n = ERROR_INDEX, @msg = MESSAGE_TEXT;

SELECT @n, @msg;

@n	@msg

4	Duplicate entry '1' for key 'PRIMARY'

DELETE FROM t;

INSERT INTO spd VALUES (1),(2),(3),(13);

UPDATE spd SET id = id + 10;

ERROR 23000: Duplicate entry '13' for key 'PRIMARY'

GET DIAGNOSTICS CONDITION 1 @n = ERROR_INDEX, @msg = MESSAGE_TEXT;

SELECT @n, @msg;

@n	@msg

1	Duplicate entry '13' for key 'PRIMARY'