Make a forum post on moodle.org, and try to insert the waving hand emoji (WAVING HAND SIGN Unicode character - the tracker can't cope with it either!).

Expected result: it works.

Actual result: database error (both via Atto autosave, and if you try to save the post).

I assume this is a Moodle.org DB configuration issue, but it could be a Moodle core issue. (On this Mac laptop with Postgres, it just works.)