BUG#884184: Wrong result with RIGHT JOIN + derived_merge

- Make eliminate_tables_for_list() take into account that it is not possible
  to eliminate a table if it is used in the upper-side ON expressions. Example:

    xxx JOIN (t1 LEFT JOIN t2 ON cond ) ON func(t2.columns)

  Here it would eliminate t2 which is not possible because of use of t2.columns.

mysql-test/r/table_elim.result

@@ -566,3 +566,22 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 # ^^ The above must not produce a QEP of t3,t5,t2,t4
 #    as that violates the "no interleaving of outer join nests" rule.
 DROP TABLE t1,t2,t3,t4,t5;
+#
+# BUG#884184: Wrong result with RIGHT JOIN + derived_merge
+#
+CREATE TABLE t1 (a int(11), b varchar(1)) ;
+INSERT IGNORE INTO t1 VALUES (0,'g');
+CREATE TABLE t3 ( a varchar(1)) ;
+INSERT IGNORE INTO t3 VALUES ('g');
+CREATE TABLE t2 ( a int(11) NOT NULL, PRIMARY KEY (a)) ;
+create view v1 as SELECT t1.* FROM t1 LEFT JOIN t2 ON ( t1.a = t2.a ) WHERE t2.a <> 0;
+SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
+a	b
+NULL	NULL
+EXPLAIN SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t3	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.a	1	Using index
+drop view v1;
+DROP TABLE t1,t2,t3;

mysql-test/t/table_elim.test

@@ -499,3 +499,21 @@ WHERE t3.f2 ;
 
 DROP TABLE t1,t2,t3,t4,t5;
 
+--echo #
+--echo # BUG#884184: Wrong result with RIGHT JOIN + derived_merge
+--echo #
+CREATE TABLE t1 (a int(11), b varchar(1)) ;
+INSERT IGNORE INTO t1 VALUES (0,'g');
+
+CREATE TABLE t3 ( a varchar(1)) ;
+INSERT IGNORE INTO t3 VALUES ('g');
+
+CREATE TABLE t2 ( a int(11) NOT NULL, PRIMARY KEY (a)) ;
+create view v1 as SELECT t1.* FROM t1 LEFT JOIN t2 ON ( t1.a = t2.a ) WHERE t2.a <> 0;
+
+SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
+EXPLAIN SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
+
+drop view v1;
+DROP TABLE t1,t2,t3;
+

sql/opt_table_elimination.cc

@@ -695,6 +695,8 @@ eliminate_tables_for_list(JOIN *join, List<TABLE_LIST> *join_list,
     {
       table_map outside_used_tables= tables_used_elsewhere | 
                                      tables_used_on_left;
+      if (on_expr)
+        outside_used_tables |= on_expr->used_tables();
       if (tbl->nested_join)
       {
         /* This is  "... LEFT JOIN (join_nest) ON cond" */