change partition key type to a not allowed type should report error

[aytrack]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t1 (a tinyint, b char) partition by range (a) (
    partition p0 values less than (10)
);
alter table t1 modify a char;

2. What did you expect to see? (Required)

MySQL test> alter table t1 modify a char;
(1659, "Field 'a' is of a not allowed type for this type of partitioning")

3. What did you see instead (Required)

TiDB root@127.0.0.1:test> alter table t1 modify a char;
show create Query OK, 0 rows affected
Time: 3.020s
TiDB root@127.0.0.1:test> show create table t1\G
***************************[ 1. row ]***************************
Table        | t1
Create Table | CREATE TABLE `t1` (
  `a` char(1) DEFAULT NULL,
  `b` char(1) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin
PARTITION BY RANGE (`a`)
(PARTITION `p0` VALUES LESS THAN (10))

1 row in set

4. What is your TiDB version? (Required)

TiDB root@127.0.0.1:test> select tidb_version()\G
***************************[ 1. row ]***************************
tidb_version() | Release Version: v6.4.0-alpha
Edition: Community
Git Commit Hash: 85b53e18781d459074f1637998014b37231283b0
Git Branch: heads/refs/tags/v6.4.0-alpha
UTC Build Time: 2022-10-22 14:24:45
GoVersion: go1.19.1
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: tikv

1 row in set

[jiyfhust]

/assign

[mjonss]

Fixed by #38670
Now returns:

tidb> alter table t1 modify a char;
ERROR 8200 (HY000): Unsupported modify column: table is partition table