Fixed LP bug #838633.

For any query JOIN::optimize() should call the method
SELECT::save_leaf_tables after the last transformation
that utilizes the statement memory rather than the 
execution memory.
  

mysql-test/r/join_outer.result

@@ -1615,3 +1615,36 @@ a	a
 4	NULL
 DEALLOCATE PREPARE stmt;
 DROP TABLE t1,t2;
+#
+# LP bug #838633: second execution of PS with outer join
+#                 converted to inner join
+#
+CREATE TABLE t1 ( b int NOT NULL ) ;
+INSERT INTO t1 VALUES (9),(10);
+CREATE TABLE t2 ( b int NOT NULL, PRIMARY KEY (b)) ;
+INSERT INTO t2 VALUES 
+(75),(76),(77),(78),(79),(80),(81),(82),(83),(84),(85),(86),(87),(88),(89),
+(10), (90),(91),(92),(93),(94),(95),(96),(97),(98),(99),(100);
+CREATE TABLE t3 ( a int, b int NOT NULL , PRIMARY KEY (b)) ;
+INSERT INTO t3 VALUES 
+(0,6),(0,7),(0,8),(2,9),(0,10),(2,21),(0,22),(2,23),(2,24),(2,25);
+SET SESSION join_cache_level=4;
+EXPLAIN EXTENDED
+SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t3	hash_ALL	PRIMARY	#hash#PRIMARY	4	test.t1.b	10	10.00	Using join buffer (flat, BNLH join)
+1	SIMPLE	t2	hash_index	PRIMARY	#hash#PRIMARY:PRIMARY	4:4	test.t1.b	27	3.70	Using join buffer (incremental, BNLH join)
+Warnings:
+Note	1003	select `test`.`t2`.`b` AS `b`,`test`.`t1`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t2` join `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`b` = `test`.`t1`.`b`) and (`test`.`t2`.`b` = `test`.`t1`.`b`))
+PREPARE stmt FROM
+'SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b';
+EXECUTE stmt;
+b	b	a	b
+10	10	0	10
+EXECUTE stmt;
+b	b	a	b
+10	10	0	10
+DEALLOCATE PREPARE stmt;
+SET SESSION join_cache_level=default;
+DROP TABLE t1,t2,t3;

mysql-test/r/join_outer_jcl6.result

@@ -1624,6 +1624,39 @@ a	a
 4	NULL
 DEALLOCATE PREPARE stmt;
 DROP TABLE t1,t2;
+#
+# LP bug #838633: second execution of PS with outer join
+#                 converted to inner join
+#
+CREATE TABLE t1 ( b int NOT NULL ) ;
+INSERT INTO t1 VALUES (9),(10);
+CREATE TABLE t2 ( b int NOT NULL, PRIMARY KEY (b)) ;
+INSERT INTO t2 VALUES 
+(75),(76),(77),(78),(79),(80),(81),(82),(83),(84),(85),(86),(87),(88),(89),
+(10), (90),(91),(92),(93),(94),(95),(96),(97),(98),(99),(100);
+CREATE TABLE t3 ( a int, b int NOT NULL , PRIMARY KEY (b)) ;
+INSERT INTO t3 VALUES 
+(0,6),(0,7),(0,8),(2,9),(0,10),(2,21),(0,22),(2,23),(2,24),(2,25);
+SET SESSION join_cache_level=4;
+EXPLAIN EXTENDED
+SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t3	hash_ALL	PRIMARY	#hash#PRIMARY	4	test.t1.b	10	10.00	Using join buffer (flat, BNLH join)
+1	SIMPLE	t2	hash_index	PRIMARY	#hash#PRIMARY:PRIMARY	4:4	test.t1.b	27	3.70	Using join buffer (incremental, BNLH join)
+Warnings:
+Note	1003	select `test`.`t2`.`b` AS `b`,`test`.`t1`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t2` join `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`b` = `test`.`t1`.`b`) and (`test`.`t2`.`b` = `test`.`t1`.`b`))
+PREPARE stmt FROM
+'SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b';
+EXECUTE stmt;
+b	b	a	b
+10	10	0	10
+EXECUTE stmt;
+b	b	a	b
+10	10	0	10
+DEALLOCATE PREPARE stmt;
+SET SESSION join_cache_level=default;
+DROP TABLE t1,t2,t3;
 set join_cache_level=default;
 show variables like 'join_cache_level';
 Variable_name	Value

mysql-test/t/join_outer.test

@@ -1173,3 +1173,37 @@ EXECUTE stmt;
 DEALLOCATE PREPARE stmt;
 
 DROP TABLE t1,t2;
+
+--echo #
+--echo # LP bug #838633: second execution of PS with outer join
+--echo #                 converted to inner join
+--echo #
+
+CREATE TABLE t1 ( b int NOT NULL ) ;
+INSERT INTO t1 VALUES (9),(10);
+
+CREATE TABLE t2 ( b int NOT NULL, PRIMARY KEY (b)) ;
+INSERT INTO t2 VALUES 
+  (75),(76),(77),(78),(79),(80),(81),(82),(83),(84),(85),(86),(87),(88),(89),
+  (10), (90),(91),(92),(93),(94),(95),(96),(97),(98),(99),(100);
+
+CREATE TABLE t3 ( a int, b int NOT NULL , PRIMARY KEY (b)) ;
+INSERT INTO t3 VALUES 
+  (0,6),(0,7),(0,8),(2,9),(0,10),(2,21),(0,22),(2,23),(2,24),(2,25);
+
+SET SESSION join_cache_level=4;
+
+EXPLAIN EXTENDED
+SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b;
+
+PREPARE stmt FROM
+'SELECT * FROM (t2 LEFT JOIN t1 ON t1.b = t2.b) JOIN t3 ON t1.b = t3.b';
+
+EXECUTE stmt;
+EXECUTE stmt;
+
+DEALLOCATE PREPARE stmt;
+
+SET SESSION join_cache_level=default;
+
+DROP TABLE t1,t2,t3;

sql/sql_select.cc

@@ -899,9 +899,6 @@ JOIN::optimize()
     /* dump_TABLE_LIST_graph(select_lex, select_lex->leaf_tables); */
     select_lex->update_used_tables();
 
-    /* Save this info for the next executions */
-    if (select_lex->save_leaf_tables(thd))
-      DBUG_RETURN(1);
   }
   
   eval_select_list_used_tables();
@@ -961,6 +958,8 @@ JOIN::optimize()
 
     /* Convert all outer joins to inner joins if possible */
     conds= simplify_joins(this, join_list, conds, TRUE, FALSE);
+    if (select_lex->save_leaf_tables(thd))
+      DBUG_RETURN(1);
     build_bitmap_for_nested_joins(join_list, 0);
 
     sel->prep_where= conds ? conds->copy_andor_structure(thd) : 0;