BUG#877288: Wrong result with semijoin + materialization + multipart key

- when create_ref_for_key() is constructing a ref access for
  a table that's inside a SJ-Materialization nest, it may not 
  use references to fields of tables that are unside the nest (because 
  these fields will not yet have values when ref access will be used)
  
  The check was performed in the first of create_ref_for_key's loops (the 
  one which counts how many key parts are usable) but not in the second
  (the one which actually fills the TABLE_REF structure). 

mysql-test/r/subselect_sj.result

@@ -1963,4 +1963,35 @@ ERROR 42000: The SELECT would examine more than MAX_JOIN_SIZE rows; check your W
 set max_join_size= @tmp_mjs_861147;
 set optimizer_switch= @tmp_os_861147;
 DROP TABLE t1,t2,t3,t4,t5,t6;
+#
+# BUG#877288: Wrong result with semijoin + materialization + multipart key
+#
+set @tmp_877288=@@optimizer_switch;
+set optimizer_switch='semijoin=ON,materialization=ON';
+CREATE TABLE t1 ( a int) ;
+INSERT INTO t1 VALUES (19),(19),(19),(20),(20),(20),(20),(20),(20);
+CREATE TABLE t2 ( b int NOT NULL , c int NOT NULL , KEY (b,c)) ;
+INSERT INTO t2 VALUES (14,1),(15,1),(16,1),(17,1),(18,1),(19,1),(20,1);
+CREATE TABLE t3 ( a int, d int) ;
+INSERT INTO t3 VALUES (19,1),(7,1),(3,1),(3,1),(20,1),(3,1),(16,1),(17,1),(9,1),(4,1),(6,1),(15,1),(17,1);
+explain
+SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
+2	SUBQUERY	t2	ref	b	b	4	test.t3.a	1	Using index
+SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
+a
+19
+19
+19
+20
+20
+20
+20
+20
+20
+DROP TABLE t1,t2,t3;
+set optimizer_switch=@tmp_877288;
 set optimizer_switch=@subselect_sj_tmp;

mysql-test/r/subselect_sj_jcl6.result

@@ -1974,6 +1974,37 @@ ERROR 42000: The SELECT would examine more than MAX_JOIN_SIZE rows; check your W
 set max_join_size= @tmp_mjs_861147;
 set optimizer_switch= @tmp_os_861147;
 DROP TABLE t1,t2,t3,t4,t5,t6;
+#
+# BUG#877288: Wrong result with semijoin + materialization + multipart key
+#
+set @tmp_877288=@@optimizer_switch;
+set optimizer_switch='semijoin=ON,materialization=ON';
+CREATE TABLE t1 ( a int) ;
+INSERT INTO t1 VALUES (19),(19),(19),(20),(20),(20),(20),(20),(20);
+CREATE TABLE t2 ( b int NOT NULL , c int NOT NULL , KEY (b,c)) ;
+INSERT INTO t2 VALUES (14,1),(15,1),(16,1),(17,1),(18,1),(19,1),(20,1);
+CREATE TABLE t3 ( a int, d int) ;
+INSERT INTO t3 VALUES (19,1),(7,1),(3,1),(3,1),(20,1),(3,1),(16,1),(17,1),(9,1),(4,1),(6,1),(15,1),(17,1);
+explain
+SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
+2	SUBQUERY	t2	ref	b	b	4	test.t3.a	1	Using index
+SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
+a
+19
+19
+19
+20
+20
+20
+20
+20
+20
+DROP TABLE t1,t2,t3;
+set optimizer_switch=@tmp_877288;
 set optimizer_switch=@subselect_sj_tmp;
 #
 # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off

mysql-test/t/subselect_sj.test

@@ -1807,6 +1807,25 @@ set optimizer_switch= @tmp_os_861147;
 
 DROP TABLE t1,t2,t3,t4,t5,t6;
 
+--echo #
+--echo # BUG#877288: Wrong result with semijoin + materialization + multipart key
+--echo #
+set @tmp_877288=@@optimizer_switch;
+set optimizer_switch='semijoin=ON,materialization=ON';
+CREATE TABLE t1 ( a int) ;
+INSERT INTO t1 VALUES (19),(19),(19),(20),(20),(20),(20),(20),(20);
+
+CREATE TABLE t2 ( b int NOT NULL , c int NOT NULL , KEY (b,c)) ;
+INSERT INTO t2 VALUES (14,1),(15,1),(16,1),(17,1),(18,1),(19,1),(20,1);
+
+CREATE TABLE t3 ( a int, d int) ;
+INSERT INTO t3 VALUES (19,1),(7,1),(3,1),(3,1),(20,1),(3,1),(16,1),(17,1),(9,1),(4,1),(6,1),(15,1),(17,1);
+
+explain
+SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a); 
+SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a); 
+DROP TABLE t1,t2,t3;
+set optimizer_switch=@tmp_877288;
 
 # The following command must be the last one the file 
 set optimizer_switch=@subselect_sj_tmp;

sql/sql_select.cc

@@ -7360,7 +7360,8 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
       while (((~used_tables) & keyuse->used_tables) || 
 	     (keyuse->keypart != 
               (is_hash_join_key_no(key) ?
-                 keyinfo->key_part[i].field->field_index : i))) 
+                 keyinfo->key_part[i].field->field_index : i)) || 
+             !are_tables_local(j, keyuse->val->used_tables())) 
 	 keyuse++;                              	/* Skip other parts */ 
 
       uint maybe_null= test(keyinfo->key_part[i].null_bit);