A bug in the restore_prev_nj_state function allowed interleaving 
inner tables of outer join operations with outer tables. With the
current implementation of the nested loops algorithm it could lead
to wrong result sets for queries with nested outer joins.
Another bug in this procedure effectively blocked evaluation of some
valid execution plans for queries with nested outer joins. 


mysql-test/r/join_nested.result:
  Added a test case for bug #29604.
mysql-test/t/join_nested.test:
  Added a test case for bug #29604.