This query was inspired by a similar one in updateRoles here

I should mention I tested its performance on the production MariaDB, as I was worried about removing the WHERE thread clause:

mysql> UPDATE roles SET permissions = CASE id WHEN '2' THEN '' ELSE permissions END;
Query OK, 0 rows affected (0.01 sec)
Rows matched: 8709  Changed: 0  Warnings: 0

Admin roles were not affected by the errant migration, as they're special-cased here.

Additionally, admin role permissions are not determined by the user-surfaced permission system, and the role editing UI does not allow editing admin permissions. Instead, admin permissions are determined directly by getRolePermissionBlobs. If we were to include them here, it would require adding some special cases below.

That's a fair concern, so I did some testing to make sure it was okay.

I constructed a fake query with the same amount of entries as follows:

let query = 'UPDATE roles SET permissions = CASE id ';
for (let i = 0; i < 8709; i++) {
  query += `WHEN '-${i}' THEN '' `;
}
query += 'ELSE permissions END';

I then ran this query on my production keyserver:

Query OK, 0 rows affected (3.24 sec)
Rows matched: 8714  Changed: 0  Warnings: 0

Technically this is just a little shorter than the real query, since the IDs are shorter. But I think it should be okay.