Unexpected results when querying information_schema

This issue is similar (but not exactly the same) to an issue I've reported earlier under MDEV-4335.

I'm using information_schema.SCHEMATA to make sure that a database exists before switching to it in my PHP app.

The issue:

The following query unexpectedly returns an empty result set on this version (I've had no issues on previous versions, except the one in the issue I've mentioned before):

SELECT `id`, `db`, `appv`, `group`, `name` FROM `web_dbs` WHERE `db` IN (SELECT `SCHEMA_NAME` FROM information_schema.SCHEMATA) ORDER BY `db` DESC;

This is unexpected, because the following query returns multiple rows, while it should be more restrictive:

SELECT `id`, `db`, `appv`, `group`, `name` FROM `web_dbs` WHERE `group` IN (SELECT `group` FROM `web_users` WHERE `username` = '[REDACTED]') AND `db` IN (SELECT `SCHEMA_NAME` FROM information_schema.SCHEMATA) ORDER BY `db` DESC;

Upon further research I found out that removing the ORDER BY clause from the first query helps, so for now I will change the first query into the following, which does work (but will probably have decreased performance):

SELECT * FROM (SELECT `id`, `db`, `appv`, `group`, `name` FROM `web_dbs` WHERE `db` IN (SELECT `SCHEMA_NAME` FROM information_schema.SCHEMATA)) tbl ORDER BY `db`;