A DDL job cannot be continued or rolled back

[mybjlife]

The original issue is from the parent project:
polardb/polardbx#3

Repro steps:

1. Create a table:
   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. Drop the primary key, drop a column and add a new primary key:
   ALTER TABLE test
   DROP PRIMARY KEY,
   DROP COLUMN col2,
   ADD PRIMARY KEY (id) USING BTREE;

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

4. "SHOW FULL DDL" returns a PAUSED DDL job.

5. Cannot rollback the DDL job via CANCEL DDL.