Commit f49842d1 introduced the
concept of a child join, but did not update this code accordingly.

Ashutosh Bapat, with cosmetic changes by me

Discussion: http://postgr.es/m/CAFjFpRf=J_KPOtw+bhZeURYkbizr8ufSaXg6gPEF6DKpgH-t6g@mail.gmail.com