Fix of MDEV-3799.

Find left table in right join (which turned to left join by reordering tables in join list but phisical order of tables of SELECT left as it was).

mysql-test/r/derived_view.result

@@ -1677,6 +1677,7 @@ SELECT t.b, t.c, t1.a
 FROM t1, (SELECT t2.b, t2.c FROM t3 RIGHT JOIN t2 ON t2.a = t3.b) AS t
 WHERE t.b AND t.c = t1.a;
 b	c	a
+8	c	c
 EXPLAIN EXTENDED
 SELECT t.b, t.c, t1.a
 FROM t1, (SELECT t2.b, t2.c FROM t3 RIGHT JOIN t2 ON t2.a = t3.b) AS t
@@ -1691,6 +1692,7 @@ SELECT t.b, t.c, t1.a
 FROM t1, (SELECT t2.b, t2.c FROM t3 RIGHT JOIN t2 ON t2.a = t3.b) AS t
 WHERE t.b <> 0 AND t.c = t1.a;
 b	c	a
+8	c	c
 INSERT INTO t3 VALUES (100), (200);
 EXPLAIN EXTENDED
 SELECT t.b, t.c, t1.a
@@ -1706,7 +1708,7 @@ SELECT t.b, t.c, t1.a
 FROM t1, (SELECT t2.b, t2.c FROM t3 RIGHT JOIN t2 ON t2.a = t3.b) AS t
 WHERE t.b AND t.c = t1.a;
 b	c	a
-NULL	NULL	c
+8	c	c
 EXPLAIN EXTENDED
 SELECT t.b, t.c, t1.a
 FROM t1, (SELECT t2.b, t2.c FROM t3 RIGHT JOIN t2 ON t2.a = t3.b) AS t
@@ -1721,7 +1723,7 @@ SELECT t.b, t.c, t1.a
 FROM t1, (SELECT t2.b, t2.c FROM t3 RIGHT JOIN t2 ON t2.a = t3.b) AS t
 WHERE t.b <> 0 AND t.c = t1.a;
 b	c	a
-NULL	NULL	c
+8	c	c
 SET optimizer_switch=@save_optimizer_switch;
 DROP TABLE t1,t2,t3;
 #

mysql-test/r/view.result

@@ -4588,6 +4588,28 @@ INSERT INTO v2 (f1, f2) VALUES (1, 2);
 ERROR HY000: Can not modify more than one base table through a join view 'test.v2'
 drop view v4,v3,v2,v1;
 drop table t1,t2;
+#
+# MDEV-3799 fix of above bugfix (MDEV-589) 
+# Wrong result (NULLs instead of real values) with RIGHT JOIN
+# in a FROM subquery and derived_merge=on
+#
+CREATE TABLE t1 (f1 INT) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (4),(6);
+CREATE TABLE t2 (f2 INT) ENGINE=MyISAM;
+INSERT INTO t2 VALUES (7),(8);
+SELECT * FROM (  
+SELECT * FROM t1 RIGHT JOIN t2 ON f1 = f2
+) AS alias;
+f1	f2
+NULL	7
+NULL	8
+SELECT * FROM (  
+SELECT * FROM t2 LEFT JOIN t1 ON f1 = f2
+) AS alias;
+f2	f1
+7	NULL
+8	NULL
+drop tables t1,t2;
 # -----------------------------------------------------------------
 # -- End of 5.3 tests.
 # -----------------------------------------------------------------

mysql-test/t/view.test

@@ -4526,6 +4526,29 @@ INSERT INTO v2 (f1, f2) VALUES (1, 2);
 drop view v4,v3,v2,v1;
 drop table t1,t2;
 
+--echo #
+--echo # MDEV-3799 fix of above bugfix (MDEV-589) 
+--echo # Wrong result (NULLs instead of real values) with RIGHT JOIN
+--echo # in a FROM subquery and derived_merge=on
+--echo #
+
+CREATE TABLE t1 (f1 INT) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (4),(6);
+
+CREATE TABLE t2 (f2 INT) ENGINE=MyISAM;
+INSERT INTO t2 VALUES (7),(8);
+
+SELECT * FROM (  
+  SELECT * FROM t1 RIGHT JOIN t2 ON f1 = f2
+) AS alias;
+
+SELECT * FROM (  
+  SELECT * FROM t2 LEFT JOIN t1 ON f1 = f2
+) AS alias;
+
+drop tables t1,t2;
+
+
 --echo # -----------------------------------------------------------------
 --echo # -- End of 5.3 tests.
 --echo # -----------------------------------------------------------------

sql/table.cc

@@ -4462,7 +4462,16 @@ TABLE *TABLE_LIST::get_real_join_table()
     tbl= (tbl->view != NULL ?
           tbl->view->select_lex.get_table_list() :
           tbl->derived->first_select()->get_table_list());
+
+    /* find left table in outer join on this level */
+    while(tbl->outer_join & JOIN_TYPE_RIGHT)
+    {
+      DBUG_ASSERT(tbl->next_local);
+      tbl= tbl->next_local;
+    }
+
   }
+
   return tbl->table;
 }