InnoDB		0 transactions not purged
#
# MDEV-17793 Crash in purge after instant DROP and emptying the table
#
connect  prevent_purge,localhost,root;
START TRANSACTION WITH CONSISTENT SNAPSHOT;
connection default;
CREATE TABLE t1 (f1 INT, f2 INT) ENGINE=InnoDB;
INSERT INTO t1 () VALUES ();
ALTER TABLE t1 DROP f2, ADD COLUMN f2 INT;
ALTER TABLE t1 DROP f1;
DELETE FROM t1;
connection prevent_purge;
COMMIT;
START TRANSACTION WITH CONSISTENT SNAPSHOT;
connection default;
ALTER TABLE t1 ADD COLUMN extra TINYINT UNSIGNED NOT NULL DEFAULT 42;
SET GLOBAL innodb_max_purge_lag_wait=1;
ALTER TABLE t1 DROP extra;
disconnect prevent_purge;
InnoDB		0 transactions not purged
DROP TABLE t1;