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--source include/have_innodb.inc
--source include/have_debug.inc
--source include/have_debug_sync.inc
--source include/count_sessions.inc
--connect (pause_purge,localhost,root)
START TRANSACTION WITH CONSISTENT SNAPSHOT;
--connection default
CREATE TABLE t (pk int PRIMARY KEY, sk INT UNIQUE) ENGINE=InnoDB;
INSERT INTO t VALUES (10, 100);
--connect (con1,localhost,root)
BEGIN; # trx 0
SELECT * FROM t WHERE sk = 100 FOR UPDATE;
--connect (con2,localhost,root)
SET DEBUG_SYNC="lock_wait_suspend_thread_enter SIGNAL insert_wait_started";
# trx 1 is locked on try to read the record in secondary index during duplicates
# check. It's the first in waiting queue, that's why it will be woken up firstly
# when trx 0 commits.
--send INSERT INTO t VALUES (5, 100) # trx 1
--connect (con3,localhost,root)
# MDEV-30225 is fixed only for RR
SET TRANSACTION ISOLATION LEVEL REPEATABLE READ;
SET DEBUG_SYNC="now WAIT_FOR insert_wait_started";
SET DEBUG_SYNC="lock_wait_suspend_thread_enter SIGNAL delete_started_waiting";
# trx 2 can delete (5, 100) on master, but not on slave, as on slave trx 1
# can insert (5, 100) after trx 2 positioned it's cursor. Trx 2 lock is placed
# in waiting queue after trx 1 lock, but its persistent cursor position was
# stored on (100, 10) record in secondary index before suspending. After trx 1
# is committed, trx 2 will restore persistent cursor position on (100, 10). As
# (100, 5) secondary index record was inserted before (100, 10) in logical
# order, and (100, 10) record is delete-marked, trx 2 just continues scanning.
#
# Note. There can be several records with the same key in unique secondary
# index, but only one of them must be non-delete-marked. That's why when we do
# point query, cursor position is set in the first record in logical order, and
# then records are iterated until either non-delete-marked record is found or
# all records with the same unique fields are iterated.
--send DELETE FROM t WHERE sk = 100 # trx 2
--connection con1
SET DEBUG_SYNC="now WAIT_FOR delete_started_waiting";
DELETE FROM t WHERE sk=100; # trx 0
COMMIT;
--disconnect con1
--connection con2
--reap
--disconnect con2
--connection con3
# If the bug is fixed, deadlock error will be there, as trx 2 owns
# next-key lock waiting for trx 1, and trx 1 requests
# insert-intention lock, conflicting with trx 2 next-key lock.
--error ER_LOCK_DEADLOCK
--reap
--disconnect con3
--connection default
# If the bug is not fixed, we will see the row inserted by trx 1 here. This can
# cause duplicate key error on slave, when some other trx tries in insert row
# with the same secondary key, as was inserted by trx 1, and not deleted by trx
# 2.
SELECT * FROM t;
--disconnect pause_purge
SET DEBUG_SYNC="RESET";
DROP TABLE t;
--source include/wait_until_count_sessions.inc
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