mariadb/mysql-test/suite/innodb/t/instant_alter_debug.test

--source include/have_innodb.inc
--source include/have_debug.inc
--source include/have_debug_sync.inc
--source include/have_sequence.inc

SET @save_stats_persistent = @@GLOBAL.innodb_stats_persistent;
SET GLOBAL innodb_stats_persistent = 0;

SET @old_instant=
(SELECT variable_value FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column');

CREATE TABLE t1 (
 pk INT AUTO_INCREMENT PRIMARY KEY,
 c1 INT,
 c2 VARCHAR(255),
 c3 VARCHAR(255),
 c4 INT,
 c5 INT,
 c6 INT,
 c7 VARCHAR(255),
 c8 TIMESTAMP NULL
) ENGINE=InnoDB;
INSERT INTO t1 VALUES (NULL,1,NULL,'foo',NULL,1,NULL,NULL,'2011-11-11 00:00:00');
ALTER TABLE t1 ADD COLUMN f INT;
REPLACE INTO t1 (c7) VALUES ('bar');

CREATE TABLE t2 (i INT PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t2 VALUES (-1),(1);
ALTER TABLE t2 ADD COLUMN j INT;
BEGIN;
DELETE FROM t2;
ROLLBACK;
TRUNCATE TABLE t2;
INSERT INTO t2 VALUES (1,2);

CREATE TABLE t3 (pk INT AUTO_INCREMENT PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t3 () VALUES ();
ALTER TABLE t3 ADD COLUMN f INT;
UPDATE t3 SET pk = DEFAULT;
SELECT * FROM t3;

CREATE TABLE t4 (pk INT PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t4 VALUES (0);
ALTER TABLE t4 ADD COLUMN b INT;
SELECT COUNT(*)>0 FROM INFORMATION_SCHEMA.COLUMNS
LEFT JOIN t4 ON (NUMERIC_SCALE = pk);
ALTER TABLE t4 ADD COLUMN c INT;

CREATE TABLE t5 (i INT, KEY(i)) ENGINE=InnoDB;
INSERT INTO t5 VALUES (-42);
ALTER TABLE t5 ADD UNIQUE ui(i);
ALTER TABLE t5 ADD COLUMN i2 INT, DROP INDEX i;

CREATE TABLE t6 (i INT NOT NULL) ENGINE=InnoDB;
INSERT INTO t6 VALUES (0);
ALTER TABLE t6 ADD COLUMN j INT;
TRUNCATE TABLE t6;
INSERT INTO t6 VALUES (1,2);

CREATE TABLE t7 (i INT) ENGINE=InnoDB;
INSERT INTO t7 VALUES (1),(2),(3),(4),(5);
ALTER TABLE t7 ADD t TEXT DEFAULT '';

CREATE TABLE t8 (i INT) ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
INSERT INTO t8 VALUES (NULL);
ALTER TABLE t8 ADD c CHAR(3);
SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL rebuilt WAIT_FOR dml';
--send
ALTER TABLE t8 FORCE;
connect (dml,localhost,root,,);
SET DEBUG_SYNC='now WAIT_FOR rebuilt';
BEGIN;
INSERT INTO t8 SET i=1;
UPDATE t8 SET i=ISNULL(i);
ROLLBACK;
SET DEBUG_SYNC='now SIGNAL dml';
connection default;
reap;
SET DEBUG_SYNC='RESET';

CREATE TABLE t9 (
 pk INT AUTO_INCREMENT PRIMARY KEY,
 c1 BIGINT UNSIGNED,
 c2 TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
 c3 BIGINT,
 c4 VARCHAR(257) CHARACTER SET utf8,
 c5 TINYINT UNSIGNED,
 c6 TINYINT,
 c7 VARCHAR(257) CHARACTER SET latin1,
 c8 VARCHAR(257) CHARACTER SET binary
) ENGINE=InnoDB;
INSERT INTO t9 () VALUES ();
ALTER TABLE t9 ADD COLUMN IF NOT EXISTS t TIMESTAMP NULL;
SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL rebuilt WAIT_FOR dml';
--send
OPTIMIZE TABLE t9;
connection dml;
SET DEBUG_SYNC='now WAIT_FOR rebuilt';
BEGIN;
INSERT INTO t9 () VALUES (),();
UPDATE t9 SET t=current_timestamp();
ROLLBACK;
SET DEBUG_SYNC='now SIGNAL dml';
disconnect dml;
connection default;
reap;
SET DEBUG_SYNC='RESET';

CREATE TABLE t10 (pk INT DEFAULT 0 KEY) ENGINE=InnoDB;
INSERT INTO t10 (pk) VALUES (1);
ALTER TABLE t10 ADD c INT;
TRUNCATE TABLE t10;
INSERT INTO t10 VALUES (1,1),(2,2);
ALTER TABLE t10 FORCE;

CREATE TABLE t11 (
 c01 enum('a','b'),
 c02 bit,
 c03 blob,
 c04 enum('c','d'),
 c05 blob,
 c06 decimal,
 c07 char(1),
 c08 int,
 c09 char(1),
 c10 set('e','f'),
 c11 char(1),
 c12 float,
 c13 bit,
 c14 char(1),
 c15 int,
 c16 float,
 c17 decimal,
 c18 char(1) CHARACTER SET utf8 not null default '',
 c19 float,
 c20 set('g','h'),
 c21 char(1),
 c22 int,
 c23 int,
 c24 int,
 c25 set('i','j'),
 c26 decimal,
 c27 float,
 c28 char(1),
 c29 int,
 c30 enum('k','l'),
 c31 decimal,
 c32 char(1),
 c33 decimal,
 c34 bit,
 c35 enum('m','n'),
 c36 set('o','p'),
 c37 enum('q','r'),
 c38 blob,
 c39 decimal,
 c40 blob not null default '',
 c41 char(1),
 c42 int,
 c43 float,
 c44 float,
 c45 enum('s','t'),
 c46 decimal,
 c47 set('u','v'),
 c48 enum('w','x'),
 c49 set('y','z'),
 c50 float
) ENGINE=InnoDB;
INSERT INTO t11 () VALUES  ();
ALTER TABLE t11 ADD COLUMN f INT;
INSERT INTO t11 () VALUES ();
UPDATE t11 SET c22 = 1;

--source include/wait_all_purged.inc
DROP TABLE t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11;

--echo #
--echo # MDEV-15060 Assertion in row_log_table_apply_op after instant ADD
--echo # when the table is emptied during subsequent ALTER TABLE
--echo #

CREATE TABLE t1 (a INT) ENGINE=InnoDB;
INSERT INTO t1 VALUES (NULL);
ALTER TABLE t1 ADD COLUMN b INT NOT NULL;
connect stop_purge,localhost,root;
START TRANSACTION WITH CONSISTENT SNAPSHOT;
connect ddl,localhost,root,,test;
DELETE FROM t1;
INSERT INTO t1 VALUES(1, 2);
SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
send ALTER TABLE t1 FORCE;
connection default;
SET DEBUG_SYNC='now WAIT_FOR copied';

BEGIN;
INSERT INTO t1 SET b=1;
ROLLBACK;
connection stop_purge;
COMMIT;
connection default;

# Wait for purge to empty the table.
let $wait_all_purged=1;
--source include/wait_all_purged.inc
let $wait_all_purged=0;

SET DEBUG_SYNC='now SIGNAL logged';
connection ddl;
reap;
connection default;
DROP TABLE t1;
SET DEBUG_SYNC='RESET';

--echo #
--echo # MDEV-16131 Assertion failed in dict_index_t::instant_field_value()
--echo #
CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t1 SET a=0;
ALTER TABLE t1 ADD COLUMN b INT NOT NULL DEFAULT 2, ADD COLUMN c INT;

DELIMITER $$;
BEGIN NOT ATOMIC
  DECLARE c TEXT DEFAULT(SELECT CONCAT('ALTER TABLE t1 ADD (c',
                                       GROUP_CONCAT(seq SEPARATOR ' INT, c'), ' INT), ALGORITHM=INSTANT;') FROM seq_1_to_130);
  EXECUTE IMMEDIATE c;
END;
$$
DELIMITER ;$$

connection stop_purge;
START TRANSACTION WITH CONSISTENT SNAPSHOT;

connection default;
DELETE FROM t1;

connection ddl;
SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
send ALTER TABLE t1 FORCE;

connection default;
SET DEBUG_SYNC = 'now WAIT_FOR copied';
connection stop_purge;
COMMIT;
connection default;
let $wait_all_purged = 1;
--source include/wait_all_purged.inc
let $wait_all_purged = 0;
INSERT INTO t1 SET a=1;
INSERT INTO t1 SET a=2,b=3,c=4;
SET DEBUG_SYNC = 'now SIGNAL logged';

connection ddl;
reap;

connection default;
SET DEBUG_SYNC = RESET;
SELECT a, b, c FROM t1;
ALTER TABLE t1 DROP b, ALGORITHM=INSTANT;
connection stop_purge;
START TRANSACTION WITH CONSISTENT SNAPSHOT;

connection default;
DELETE FROM t1;

connection ddl;
SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
send ALTER TABLE t1 ADD COLUMN b INT NOT NULL DEFAULT 2 AFTER a, FORCE;

connection default;
SET DEBUG_SYNC = 'now WAIT_FOR copied';
disconnect stop_purge;
let $wait_all_purged = 1;
--source include/wait_all_purged.inc
let $wait_all_purged = 0;
INSERT INTO t1 SET a=1;
INSERT INTO t1 SET a=2,c=4;
SET DEBUG_SYNC = 'now SIGNAL logged';

connection ddl;
reap;
UPDATE t1 SET b = b + 1 WHERE a = 2;

connection default;
SET DEBUG_SYNC = RESET;
SELECT a, b, c FROM t1;

--echo #
--echo # MDEV-15872 Crash in online ALTER TABLE...ADD PRIMARY KEY
--echo # after instant ADD COLUMN ... NULL
--echo #
ALTER TABLE t1 ADD COLUMN d INT, ALGORITHM=INSTANT;
UPDATE t1 SET d=1;

connection ddl;
SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
send ALTER TABLE t1 DROP PRIMARY KEY, ADD PRIMARY KEY (a,d);

connection default;
SET DEBUG_SYNC = 'now WAIT_FOR copied';
BEGIN;
INSERT INTO t1 SET a=3;
ROLLBACK;
SET DEBUG_SYNC = 'now SIGNAL logged';

connection ddl;
reap;
disconnect ddl;

connection default;
SET DEBUG_SYNC = RESET;
SELECT a, b, c, d FROM t1;
DROP TABLE t1;

--echo #
--echo # MDEV-19916 Corruption after instant ADD/DROP and shrinking the tree
--echo #
CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;

# Create an index tree with 2 levels of node pointer pages.

SET @old_limit = @@innodb_limit_optimistic_insert_debug;
SET GLOBAL innodb_limit_optimistic_insert_debug = 2;
INSERT INTO t1 VALUES (1),(5),(4),(3),(2);
SET GLOBAL innodb_limit_optimistic_insert_debug = @old_limit;

ALTER TABLE t1 ADD COLUMN b INT, ALGORITHM=INSTANT;

# Exploit MDEV-17468 to force the table definition to be reloaded
ALTER TABLE t1 ADD vb INT AS (b) VIRTUAL;
CHECK TABLE t1;
SELECT * FROM t1;
DROP TABLE t1;

--echo #
--echo # MDEV-21045 AddressSanitizer: use-after-poison in mem_heap_dup / row_log_table_get_pk_col
--echo #
CREATE TABLE t1 (a TEXT) ENGINE = InnoDB ROW_FORMAT=REDUNDANT;
INSERT INTO t1 (a) VALUES ('foo');

ALTER TABLE t1 ADD COLUMN b INT DEFAULT 0,algorithm=instant;

--connect (con2,localhost,root,,test)
SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL onlinealter WAIT_FOR update';
--send
ALTER TABLE t1 ADD PRIMARY KEY (b);

--connection default
SET DEBUG_SYNC='now WAIT_FOR onlinealter';
UPDATE t1 SET b = 1;
SET DEBUG_SYNC='now SIGNAL update';

--connection con2
--reap

--connection default
DROP TABLE t1;

--echo #
--echo # MDEV-21658 Error on online ADD PRIMARY KEY after instant DROP/reorder
--echo #

CREATE TABLE t1 (a INT, b INT, c INT, col INT) ENGINE=InnoDB;
INSERT INTO t1 () VALUES ();
ALTER TABLE t1 DROP b, DROP c, DROP col;
ALTER TABLE t1 ADD COLUMN col INT;
ALTER TABLE t1 DROP a, DROP col, ADD COLUMN b INT;

--connection con2
SET SQL_MODE= '';
SET DEBUG_SYNC = 'row_log_table_apply1_before SIGNAL scanned WAIT_FOR dml';
send ALTER TABLE t1 ADD PRIMARY KEY(b);

--connection default
SET DEBUG_SYNC = 'now WAIT_FOR scanned';
UPDATE t1 SET b = 1;
SET DEBUG_SYNC = 'now SIGNAL dml';
--connection con2
reap;
--connection default
SELECT * FROM t1;

SET DEBUG_SYNC='RESET';
--disconnect con2
DROP TABLE t1;

--echo #
--echo # MDEV-24653 Assertion block->page.id.page_no() == index->page failed
--echo # in innobase_add_instant_try()
--echo #

SET @saved_limit = @@GLOBAL.innodb_limit_optimistic_insert_debug;
SET GLOBAL innodb_limit_optimistic_insert_debug = 2;

CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1),(2),(3),(4);
ALTER TABLE t1 ADD COLUMN b INT;
DELETE FROM t1;
--source include/wait_all_purged.inc
ALTER TABLE t1 ADD COLUMN c INT;

SELECT * FROM t1;
DROP TABLE t1;
SET GLOBAL innodb_limit_optimistic_insert_debug = @saved_limit;

--echo #
--echo # MDEV-24796 Assertion page_has_next... failed
--echo # in btr_pcur_store_position()
--echo #

CREATE TABLE t1 (c INT KEY) ENGINE=InnoDB;
INSERT INTO t1 VALUES(1),(2);
SET GLOBAL innodb_limit_optimistic_insert_debug=2;
ALTER TABLE t1 ADD COLUMN d INT;
DELETE FROM t1;
--source include/wait_all_purged.inc
SELECT * FROM t1 WHERE c<>1 ORDER BY c DESC;
DROP TABLE t1;

SET GLOBAL innodb_limit_optimistic_insert_debug = @saved_limit;

--echo #
--echo # MDEV-24620 ASAN heap-buffer-overflow in btr_pcur_restore_position()
--echo #

CREATE TABLE t1 (a VARCHAR(1) PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1);
connect (stop_purge,localhost,root,,);
START TRANSACTION WITH CONSISTENT SNAPSHOT;

connection default;
ALTER TABLE t1 ADD c INT;
BEGIN;
DELETE FROM t1;

connect (dml,localhost,root,,test);
SET DEBUG_SYNC='row_mysql_handle_errors SIGNAL s1 WAIT_FOR s2';
send UPDATE t1 SET c=1;

connection default;
SET DEBUG_SYNC='now WAIT_FOR s1';
COMMIT;

connection stop_purge;
COMMIT;
disconnect stop_purge;

connection default;
let $wait_all_purged = 1;
--source include/wait_all_purged.inc
let $wait_all_purged = 0;
SET DEBUG_SYNC='now SIGNAL s2';

connection dml;
reap;
disconnect dml;

connection default;
--source include/wait_all_purged.inc
SET DEBUG_SYNC=RESET;
DROP TABLE t1;

--echo # End of 10.3 tests

--echo #
--echo # MDEV-17899 Assertion failures on rollback of instant ADD/DROP
--echo # MDEV-18098 Crash after rollback of instant DROP COLUMN
--echo #

SET @save_dbug = @@SESSION.debug_dbug;
SET debug_dbug='+d,ib_commit_inplace_fail_1';
CREATE TABLE t1 (a int, b int) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1,2);
--error ER_INTERNAL_ERROR
ALTER TABLE t1 DROP COLUMN b;
--error ER_INTERNAL_ERROR
ALTER TABLE t1 DROP COLUMN b;
--error ER_INTERNAL_ERROR
ALTER TABLE t1 ADD COLUMN c INT;
SELECT * FROM t1;
DROP TABLE t1;

CREATE TABLE t1 (a int, b int) ENGINE=InnoDB;
--error ER_INTERNAL_ERROR
ALTER TABLE t1 ADD COLUMN c INT;
BEGIN;
INSERT INTO t1 VALUES(1, 1);
ROLLBACK;
--error ER_INTERNAL_ERROR
ALTER TABLE t1 DROP COLUMN b;
INSERT INTO t1 values (1,1);
SELECT * FROM t1;
DROP TABLE t1;

SET debug_dbug = @save_dbug;

--echo #
--echo # MDEV-24512 Assertion failed in rec_is_metadata()
--echo #            in btr_discard_only_page_on_level()
--echo #

SET @save_limit= @@GLOBAL.innodb_limit_optimistic_insert_debug;
SET GLOBAL innodb_limit_optimistic_insert_debug=2;
CREATE TABLE t1 (c CHAR(1) UNIQUE) ENGINE=InnoDB;

ALTER TABLE t1 ADD c2 INT NOT NULL DEFAULT 0 FIRST;
--error ER_DUP_ENTRY
INSERT INTO t1 (c) VALUES ('x'),('d'),('r'),('f'),('y'),('u'),('m'),('d');
SET GLOBAL innodb_limit_optimistic_insert_debug=@save_limit;
SELECT * FROM t1;
DROP TABLE t1;

--echo #
--echo # MDEV-25236 Online log apply fails for ROW_FORMAT=REDUNDANT tables
--echo #

CREATE TABLE t1
(a INT NOT NULL, b INT, c INT, d INT, e INT, f INT, g INT, h INT, i TEXT)
ENGINE=InnoDB;
INSERT INTO t1 VALUES(1, 2, 3, 4, 5, 6, 7, 8, "test");
ALTER TABLE t1 MODIFY a INT NULL;

SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL alter WAIT_FOR go';
send ALTER TABLE t1 ADD PRIMARY KEY (a);
connect(con1,localhost,root,,);
set DEBUG_SYNC='now WAIT_FOR alter';
BEGIN;
INSERT INTO t1 SET a=0, i=REPEAT('1', 10000);
ROLLBACK;
set DEBUG_SYNC='now SIGNAL go';
connection default;
reap;

SELECT * FROM t1;
DROP TABLE t1;
SET DEBUG_SYNC=RESET;

--echo #
--echo # MDEV-27962 Instant DDL downgrades the MDL when table is empty
--echo #
CREATE TABLE t1(f1 INT NOT NULL, f2 INT NOT NULL)ENGINE=InnoDB;
SET DEBUG_SYNC="alter_table_inplace_after_lock_downgrade SIGNAL try_insert WAIT_FOR alter_progress";
send ALTER TABLE t1 ADD INDEX(f1), ADD INDEX(f2);
connection con1;
SET SESSION lock_wait_timeout=1;
SET DEBUG_SYNC="now WAIT_FOR try_insert";
--error ER_LOCK_WAIT_TIMEOUT
INSERT INTO t1 VALUES(1, 2);
SET DEBUG_SYNC="now SIGNAL alter_progress";
connection default;
reap;
DROP TABLE t1;

--echo #
--echo #  MDEV-26198 Assertion `0' failed in row_log_table_apply_op during
--echo #                ADD PRIMARY KEY or OPTIMIZE TABLE
--echo #
CREATE TABLE t1(f1 year default null, f2 year default null,
                f3 text, f4 year default null, f5 year default null,
                f6 year default null, f7 year default null,
                f8 year default null)ENGINE=InnoDB;
INSERT INTO t1 VALUES(1, 1, 1, 1, 1, 1, 1, 1);
ALTER TABLE t1 ADD COLUMN f9 year default null, ALGORITHM=INPLACE;
set DEBUG_SYNC="row_log_table_apply1_before SIGNAL con1_insert WAIT_FOR con1_finish";
send ALTER TABLE t1 ADD COLUMN f10 YEAR DEFAULT NULL, FORCE, ALGORITHM=INPLACE;

connection con1;
SET DEBUG_SYNC="now WAIT_FOR con1_insert";
INSERT IGNORE INTO t1 (f3) VALUES ( 'b' );
INSERT IGNORE INTO t1 (f3) VALUES ( 'l' );
SET DEBUG_SYNC="now SIGNAL con1_finish";

connection default;
reap;
CHECK TABLE t1;
DROP TABLE t1;

--echo #
--echo # MDEV-19044 Alter table corrupts while applying the
--echo #             modification log
--echo #
CREATE TABLE t1 (
        f1 INT,
        f2 INT,
        f3 char(19) CHARACTER SET utf8mb3,
        f4 VARCHAR(500),
        f5 TEXT)ENGINE=InnoDB;
INSERT INTO t1 VALUES(3, 1, REPEAT('a', 2), REPEAT("b", 20),'a');
ALTER TABLE t1 ADD COLUMN f6 INT NOT NULL, ALGORITHM=INSTANT;
INSERT INTO t1 VALUES(1, 2, REPEAT('InnoDB', 2),
                      REPEAT("MariaDB", 20), REPEAT('a', 8000), 12);
INSERT INTO t1 VALUES(1, 2, REPEAT('MYSQL', 2),
                      REPEAT("MariaDB", 20), REPEAT('a', 8000), 12);
SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL con1_begin WAIT_FOR con1_update';
send ALTER TABLE t1 MODIFY COLUMN f2 INT NOT NULL, FORCE, ALGORITHM=INPLACE;
connection con1;
SET DEBUG_SYNC='now WAIT_FOR con1_begin';
UPDATE t1 SET f2=204 order by f1 limit 2;
SET DEBUG_SYNC='now SIGNAL con1_update';
connection default;
reap;
disconnect con1;
SET DEBUG_SYNC=reset;
CHECK TABLE t1;
DROP TABLE t1;

--echo # End of 10.4 tests

--echo #
--echo # MDEV-22867 Assertion instant.n_core_fields == n_core_fields
--echo # in dict_index_t::instant_add_field
--echo #

CREATE TABLE t1 (a INT PRIMARY KEY, b INT UNIQUE) ENGINE=InnoDB;
INSERT INTO t1 SET a=1;

connect (prevent_purge,localhost,root,,);
START TRANSACTION WITH CONSISTENT SNAPSHOT;
connection default;
ALTER TABLE t1 ADD COLUMN c INT;
DELETE FROM t1;

connect (con2,localhost,root,,test);
# FIXME: If this is implemented then also i->online_log must be checked in
# dict_index_t::must_avoid_clear_instant_add(). See the comment there.
--error ER_ALTER_OPERATION_NOT_SUPPORTED
ALTER TABLE t1 DROP b, ADD INDEX(c), ALGORITHM=NOCOPY;
SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL ddl WAIT_FOR emptied';
send ALTER TABLE t1 DROP b;

connection default;
SET DEBUG_SYNC='now WAIT_FOR ddl';
BEGIN;
INSERT INTO t1 SET a=1;

connection prevent_purge;
COMMIT;
disconnect prevent_purge;

connection default;
ROLLBACK;
SELECT * FROM t1;
SET DEBUG_SYNC='now SIGNAL emptied';

connection con2;
reap;
disconnect con2;
connection default;
ALTER TABLE t1 DROP c;
INSERT INTO t1 VALUES (2),(3),(4);
CHECK TABLE t1;
DROP TABLE t1;
SET DEBUG_SYNC=RESET;

--echo # End of 10.5 tests

SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';

SET GLOBAL innodb_stats_persistent = @save_stats_persistent;

--echo # End of 10.6 tests