MariaDB FULLTEXT search with apostrophe, and mandatory words
Works for me in both MyISAM and InnoDB.

But note:  out of 185,082 rows, 17 have "O'Brien".  That's less than 50%, so the search term is not ignored.  I verified the count with LIKE "%O'Brien%".

But, when adding the +, it needs to be outside the quotes for InnoDB.  (Yet another difference between the implementations.)

(I have updated my blog to add this diff.)