1# 2# Bug #27216817 / #88747 "InnoDB: Failing assertion: prebuilt->table->n_mysql_handles_opened == 1" 3# fixed in 5.5.60, 5.6.40, 5.7.22, 8.0.11 4# Adding a unique index to an InnoDB table on which multiple locks were 5# held could raise an assertion 6# 7CREATE TABLE t1( 8c1 INT NOT NULL, 9c2 TIMESTAMP NOT NULL, 10c3 INT NULL, 11c4 CHAR(1) NOT NULL 12) ENGINE=InnoDB; 13LOCK TABLES t1 WRITE, t1 AS a READ; 14ALTER TABLE t1 ADD PRIMARY KEY(c1); 15UNLOCK TABLES; 16DROP TABLE t1; 17