Table could be marked dependent because it is
either 1) an inner table of an outer join, or 2) it is a part of
STRAIGHT_JOIN. In case of STRAIGHT_JOIN table->maybe_null should not
be assigned. The fix is to set st_table::maybe_null to 'true' only
for those tables which are used in outer join.



mysql-test/r/select.result:
  test result
mysql-test/t/select.test:
  test case
sql/sql_select.cc:
  Table could be marked dependent because it is
  either 1) an inner table of an outer join, or 2) it is a part of
  STRAIGHT_JOIN. In case of STRAIGHT_JOIN table->maybe_null should not
  be assigned. The fix is to set st_table::maybe_null to 'true' only
  for those tables which are used in outer join.
sql/sql_select.h:
  added comment