JSON type has an unexpected NOT_NULL flag.

[SunRunAway]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t ( c_bit bit(10), c_int_d int, c_uint_d int unsigned, c_bigint_d bigint, c_ubigint_d bigint unsigned, c_float_d float, c_ufloat_d float unsigned, c_double_d double, c_udouble_d double unsigned, c_decimal decimal(6, 3), c_udecimal decimal(10, 3) unsigned, c_decimal_d decimal, c_udecimal_d decimal unsigned, c_datetime datetime(2), c_datetime_d datetime, c_time time(3), c_time_d time, c_date date, c_timestamp timestamp(4) DEFAULT CURRENT_TIMESTAMP(4), c_timestamp_d timestamp DEFAULT CURRENT_TIMESTAMP, c_char char(20), c_bchar char(20) binary, c_varchar varchar(20), c_bvarchar varchar(20) binary, c_text_d text, c_btext_d text binary, c_binary binary(20), c_varbinary varbinary(20), c_blob_d blob, c_set set('a', 'b', 'c'), c_enum enum('a', 'b', 'c'), c_json JSON, c_year year );

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

mysql> select c_json from t;
Field   1:  `c_json`
Catalog:    `def`
Database:   `test`
Table:      `t`
Org_table:  `t`
Type:       JSON
Collation:  binary (63)
Length:     4294967295
Max_length: 0
Decimals:   0
Flags:      BLOB BINARY 


0 rows in set (0.02 sec)

3. What did you see instead (Required)

mysql> select c_json from t;
Field   1:  `c_json`
Catalog:    `def`
Database:   `test`
Table:      `t`
Org_table:  `t`
Type:       JSON
Collation:  binary (63)
Length:     4294967295
Max_length: 0
Decimals:   0
Flags:      NOT_NULL BINARY 


0 rows in set (0.01 sec)

4. Affected version (Required)

5. Root Cause Analysis

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