WL#2486 - natural and using join according to SQL:2003

- Corrected problem with N-way nested natural joins in PS mode.
- Code cleanup
- More asserts to check consistency of name resolution contexts
- Fixed potential memory leak of name resolution contexts


mysql-test/r/join.result:
  - Corrected problem with N-way nested natural joins in PS mode.
mysql-test/t/join.test:
  - Corrected problem with N-way nested natural joins in PS mode.
sql/item.h:
  - Fixed potential memory leak.
sql/sql_base.cc:
  - the local context of Item_fields that participate in TABLE_LIST::on_cond for
    natural joins is correctly set to the tables where the corresponding fields
    originate from.
  - removed unused variables
  - correct allocation of contexts
sql/sql_parse.cc:
  - correct allocation of contexts for JOIN ON conditions.
sql/table.cc:
  - added asserts to check the consistency of name resolution contexts
sql/table.h:
  - added asserts to check the consistency of name resolution contexts

1 files changed, 1 insertions, 3 deletions

diff --git a/mysql-test/t/join.test b/mysql-test/t/join.test
index 06e89e6cb9d..2e82bad8abb 100644
--- a/mysql-test/t/join.test
+++ b/mysql-test/t/join.test
@@ -111,9 +111,7 @@ drop table t1, t2;
 
 create table t1 (a int primary key);
 insert into t1 values(1),(2);
-# TODO: WL#2486 - the query fails in PS mode with error:
-#       Cross dependency found in OUTER JOIN; examine your ON conditions
-#select a from t1 as t1 left join t1 as t2 using (a) left join t1 as t3 using (a) left join t1 as t4 using (a) left join t1 as t5 using (a) left join t1 as t6 using (a) left join t1 as t7 using (a) left join t1 as t8 using (a) left join t1 as t9 using (a) left join t1 as t10 using (a) left join t1 as t11 using (a) left join t1 as t12 using (a) left join t1 as t13 using (a) left join t1 as t14 using (a) left join t1 as t15 using (a) left join t1 as t16 using (a) left join t1 as t17 using (a) left join t1 as t18 using (a) left join t1 as t19 using (a) left join t1 as t20 using (a) left join t1 as t21 using (a) left join t1 as t22 using (a) left join t1 as t23 using (a) left join t1 as t24 using (a) left join t1 as t25 using (a) left join t1 as t26 using (a) left join t1 as t27 using (a) left join t1 as t28 using (a) left join t1 as t29 using (a) left join t1 as t30 using (a) left join t1 as t31 using (a);
+select a from t1 as t1 left join t1 as t2 using (a) left join t1 as t3 using (a) left join t1 as t4 using (a) left join t1 as t5 using (a) left join t1 as t6 using (a) left join t1 as t7 using (a) left join t1 as t8 using (a) left join t1 as t9 using (a) left join t1 as t10 using (a) left join t1 as t11 using (a) left join t1 as t12 using (a) left join t1 as t13 using (a) left join t1 as t14 using (a) left join t1 as t15 using (a) left join t1 as t16 using (a) left join t1 as t17 using (a) left join t1 as t18 using (a) left join t1 as t19 using (a) left join t1 as t20 using (a) left join t1 as t21 using (a) left join t1 as t22 using (a) left join t1 as t23 using (a) left join t1 as t24 using (a) left join t1 as t25 using (a) left join t1 as t26 using (a) left join t1 as t27 using (a) left join t1 as t28 using (a) left join t1 as t29 using (a) left join t1 as t30 using (a) left join t1 as t31 using (a);
 --replace_result "31 tables" "XX tables" "61 tables" "XX tables"
 --error 1116
 select a from t1 as t1 left join t1 as t2 using (a) left join t1 as t3 using (a) left join t1 as t4 using (a) left join t1 as t5 using (a) left join t1 as t6 using (a) left join t1 as t7 using (a) left join t1 as t8 using (a) left join t1 as t9 using (a) left join t1 as t10 using (a) left join t1 as t11 using (a) left join t1 as t12 using (a) left join t1 as t13 using (a) left join t1 as t14 using (a) left join t1 as t15 using (a) left join t1 as t16 using (a) left join t1 as t17 using (a) left join t1 as t18 using (a) left join t1 as t19 using (a) left join t1 as t20 using (a) left join t1 as t21 using (a) left join t1 as t22 using (a) left join t1 as t23 using (a) left join t1 as t24 using (a) left join t1 as t25 using (a) left join t1 as t26 using (a) left join t1 as t27 using (a) left join t1 as t28 using (a) left join t1 as t29 using (a) left join t1 as t30 using (a) left join t1 as t31 using (a) left join t1 as t32 using (a) left join t1 as t33 using (a) left join t1 as t34 using (a) left join t1 as t35 using (a) left join t1 as t36 using (a) left join t1 as t37 using (a) left join t1 as t38 using (a) left join t1 as t39 using (a) left join t1 as t40 using (a) left join t1 as t41 using (a) left join t1 as t42 using (a) left join t1 as t43 using (a) left join t1 as t44 using (a) left join t1 as t45 using (a) left join t1 as t46 using (a) left join t1 as t47 using (a) left join t1 as t48 using (a) left join t1 as t49 using (a) left join t1 as t50 using (a) left join t1 as t51 using (a) left join t1 as t52 using (a) left join t1 as t53 using (a) left join t1 as t54 using (a) left join t1 as t55 using (a) left join t1 as t56 using (a) left join t1 as t57 using (a) left join t1 as t58 using (a) left join t1 as t59 using (a) left join t1 as t60 using (a) left join t1 as t61 using (a) left join t1 as t62 using (a) left join t1 as t63 using (a) left join t1 as t64 using (a) left join t1 as t65 using (a);