Fix bug mdev-447: Wrong output from the EXPLAIN command of the test case for lp bug #714999

The fix backports from MWL#182: Explain running statements the logic that
saves the original JOIN_TAB array of a query plan after optimization. This
array is later used during EXPLAIN to iterate over the original JOIN plan
nodes in the cases when this plan could be changed by early subquery
execution during the optimization phase of the outer query.

7 files changed, 8 insertions, 8 deletions

diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 3ea6c0be398..8c71c09c1ac 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -4196,7 +4196,7 @@ INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
-2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
diff --git a/mysql-test/r/subselect_innodb.result b/mysql-test/r/subselect_innodb.result
index a0f05a26a46..a4670872fad 100644
--- a/mysql-test/r/subselect_innodb.result
+++ b/mysql-test/r/subselect_innodb.result
@@ -333,7 +333,7 @@ WHERE (SELECT DISTINCT b FROM t3) > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	Using where; Using index
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-3	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	0	Using temporary
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	1	Using temporary
 SELECT *
 FROM t1
 WHERE t1.a = (
@@ -386,7 +386,7 @@ select 1 from t1 where 1 like (select 1 from t1 where 1 <=> (select 1 from t1 gr
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	1	
-3	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	1	Using temporary; Using filesort
 select 1 from t1 where 1 like (select 1 from t1 where 1 <=> (select 1 from t1 group by a1));
 1
 1
diff --git a/mysql-test/r/subselect_mat_cost_bugs.result b/mysql-test/r/subselect_mat_cost_bugs.result
index 1d03f2e9fe6..8c95c8637aa 100644
--- a/mysql-test/r/subselect_mat_cost_bugs.result
+++ b/mysql-test/r/subselect_mat_cost_bugs.result
@@ -148,7 +148,7 @@ FROM t2 GROUP BY f1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	SUBQUERY	t1	system	NULL	NULL	NULL	NULL	1	
-3	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
+3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 drop table t1, t2, t3;
 #
 # LP BUG#715034 Item_sum_distinct::clear(): Assertion `tree != 0' failed
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index 8ce097787f1..48ab96dcaaa 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -4200,7 +4200,7 @@ INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
-2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 466d8c8fd06..9ab4e23b091 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -4196,7 +4196,7 @@ INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
-2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
diff --git a/mysql-test/r/subselect_no_scache.result b/mysql-test/r/subselect_no_scache.result
index 1fde0d08d7e..d47aa956ead 100644
--- a/mysql-test/r/subselect_no_scache.result
+++ b/mysql-test/r/subselect_no_scache.result
@@ -4202,7 +4202,7 @@ INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
-2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index ba50b8522eb..96e6c2182fa 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -4196,7 +4196,7 @@ INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
-2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES