DDL任务无法删除或取消

[yahaier]

1、创建表：
CREATE TABLE test (
col1 varchar(255) DEFAULT NULL,
col2 varchar(255) NOT NULL,
id int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (id,col2)
) ENGINE = InnoDB DEFAULT CHARSET = utf8 ;

2、删除col2主键字段
ALTER TABLE test
DROP PRIMARY KEY,
DROP COLUMN col2,
ADD PRIMARY KEY (id) USING BTREE;

报错：Failed to execute the DDL task. Caused by: Illegal Capacity: -1

4、执行SHOW FULL DDL有条DDL任务执行失败，状态为：PAUSED

5、执行 CANCEL DDL job_id无法取消DDL任务

[mybjlife]

Thanks for your findings.

We can reproduce this issue and already fixed it via PR #117 in the project 'galaxysql'.