--source include/have_innodb.inc
--source include/count_sessions.inc
source include/have_debug.inc;
source include/have_debug_sync.inc;

CREATE TABLE t (a int PRIMARY KEY, b int NOT NULL UNIQUE) engine = InnoDB, STATS_PERSISTENT=0;

--source include/wait_all_purged.inc
--connect(prevent_purge,localhost,root,,)
start transaction with consistent snapshot;

--connect(con_del_1,localhost,root,,)
INSERT INTO t VALUES (20,20);
SET DEBUG_SYNC = 'innodb_row_search_for_mysql_exit SIGNAL first_del_row_search_mvcc_finished WAIT_FOR first_del_cont';
--send DELETE FROM t WHERE b = 20 # trx_1

--connect(con_ins_1,localhost,root,,)
SET DEBUG_SYNC = 'now WAIT_FOR first_del_row_search_mvcc_finished';
# It's supposed the following INSERT will be suspended just after
# lock_wait_start syncpoint, and will be awaken
# after trx_1 DELETE commits. ib_after_row_insert will be executed
# after the trx_2 INSERT is woken up. The trx_1 DELETE will wait for
# first_del_cont signal before commit, and this signal will be sent later.
# So it's safe to use two signals in a row here, it's guaranted the first
# signal will be received before the second signal is sent.
SET DEBUG_SYNC = 'lock_wait_start SIGNAL first_ins_locked';
SET DEBUG_SYNC = 'ib_after_row_insert SIGNAL first_ins_row_inserted WAIT_FOR first_ins_cont';
--send INSERT INTO t VALUES(10, 20) # trx_2

--connect(con_del_2,localhost,root,,)
# After MDEV-30225 is fixed, the following DELETE creates next-key lock for
# unqique search for RR, and the above INSERT kills it as deadlock victim.
# But it still requests not-gap lock for RC.
SET TRANSACTION ISOLATION LEVEL READ COMMITTED;
SET DEBUG_SYNC = 'now WAIT_FOR first_ins_locked';
SET DEBUG_SYNC = 'lock_wait_start SIGNAL second_del_locked';
##############################################################################
# trx_3 DELETE is locked by trx_1 DELETE, after trx_1 DELETE is
# committed, it will still be locked by trx_2 INSERT on delete-marked
# heap_no 2 record. After trx_2 INSERT inserted the record with heap_no 3,
# and after heap_no 2 record is purged, trx_3 DELETE will be unlocked and
# must restore persistent cursor position at heap_no 3 record, as it has the
# same secondary key value as former heap_no 2 record. Then it must be blocked
# by trx_2 INSERT, and after trx_2 INSERT is committed, it must
# delete the record, inserted by trx_2 INSERT, and trx_4 INSERT(see
# below) must be finished without error. But instead this DELETE restores
# persistent cursor position to supremum, as a result, it does not delete the
# record, inserted by trx_2 INSERT, and trx_4 INSERT is finished with
# duplicate key check error.
###############################################################################
--send DELETE FROM t WHERE b = 20 # trx_3

--connection default
SET DEBUG_SYNC = 'now WAIT_FOR second_del_locked';
SET @saved_dbug = @@GLOBAL.debug_dbug;
SET @@GLOBAL.debug_dbug="d,enable_row_purge_del_mark_exit_sync_point";
SET DEBUG_SYNC = 'now SIGNAL first_del_cont';
SET DEBUG_SYNC = 'now WAIT_FOR first_ins_row_inserted';
--connection con_del_1
--reap

--connection default
--disconnect prevent_purge
SET DEBUG_SYNC = 'now WAIT_FOR row_purge_del_mark_finished';
SET @@GLOBAL.debug_dbug = @saved_dbug;
SET DEBUG_SYNC = 'now SIGNAL first_ins_cont';

--connection con_del_2
--reap

--connection con_ins_1
--reap

--connection default
###############################################################################
# Duplicate key error is expected if the bug is not fixed.
###############################################################################
INSERT INTO t VALUES(30, 20); # trx_4

--disconnect con_ins_1
--disconnect con_del_1
--disconnect con_del_2
--connection default

SET DEBUG_SYNC = 'RESET';
DROP TABLE t;
--source include/wait_until_count_sessions.inc