Other databases (like PostgreSQL) allow to use subqueries that get limited number of rows in the IN(...) clause, similar to this:

SELECT ... FROM ... WHERE outer_expr IN (SELECT inner_expr FROM ... [ORDER BY ...] LIMIT n)

and the semantics is to first apply the LIMIT clause to the subquery output and then make the "outer_col IN (...)" check.

It would be nice to add support for this specific case of LIMIT in subqueries (with ORDER BY or without), as now we get a generic error message:

ERROR 1235 (42000): This version of MariaDB doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'

This specific case of IN subquery support should be implemented separately as it conflicts with current IN->EXISTS rewrite that is unique to IN subqueries.