Bug #899962: materialized subquery with join_cache_level=3

- Make create_tmp_table() set KEY_PART_INFO attributes for the keys it creates.
  This wasn't needed before but is needed now, when temp. tables that are 
  results of SJ-Materialization are being used for joins.
  This particular bug depended on HA_VAR_LENGTH_PART being set,
  but also added code to set HA_BLOB_PART and HA_NULL_PART when appropriate.

mysql-test/r/subselect_sj2_jcl6.result

@@ -955,6 +955,28 @@ pk	a	b
 set optimizer_switch=@tmp_optimizer_switch;
 set join_cache_level=default;
 DROP TABLE t1,t2,t3,t4;
+#
+# Bug #899962: materialized subquery with join_cache_level=3 
+#
+CREATE TABLE t1 (a varchar(1), b varchar(1)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES ('v','v');
+CREATE TABLE t2 (a varchar(1), b varchar(1)) ENGINE=InnoDB;
+INSERT INTO t2 VALUES ('v','v');
+set @tmp_optimizer_switch=@@optimizer_switch;
+SET optimizer_switch = 'semijoin_with_cache=on';
+SET join_cache_level = 3;
+EXPLAIN
+SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	Using where
+1	PRIMARY	<subquery2>	hash_ALL	distinct_key	#hash#distinct_key	5	test.t1.b	1	Using join buffer (flat, BNLH join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	1	Using temporary
+SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
+a	b
+v	v
+set optimizer_switch=@tmp_optimizer_switch;
+set join_cache_level=default;
+DROP TABLE t1,t2;
 set join_cache_level=default;
 show variables like 'join_cache_level';
 Variable_name	Value

mysql-test/t/subselect_sj2_jcl6.test

@@ -73,6 +73,30 @@ set join_cache_level=default;
 DROP TABLE t1,t2,t3,t4;
 
 
+--echo #
+--echo # Bug #899962: materialized subquery with join_cache_level=3 
+--echo #
+
+CREATE TABLE t1 (a varchar(1), b varchar(1)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES ('v','v');
+CREATE TABLE t2 (a varchar(1), b varchar(1)) ENGINE=InnoDB;
+INSERT INTO t2 VALUES ('v','v');
+
+set @tmp_optimizer_switch=@@optimizer_switch;
+
+SET optimizer_switch = 'semijoin_with_cache=on';
+SET join_cache_level = 3;
+
+EXPLAIN
+SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
+SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
+
+set optimizer_switch=@tmp_optimizer_switch;
+set join_cache_level=default;
+
+DROP TABLE t1,t2;
+
+
 set join_cache_level=default;
 show variables like 'join_cache_level';
 

sql/sql_select.cc

@@ -13937,10 +13937,22 @@ create_tmp_table(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields,
       key_part_info->store_length= key_part_info->length;
 
       if ((*reg_field)->real_maybe_null())
+      {
         key_part_info->store_length+= HA_KEY_NULL_LENGTH;
-      if ((*reg_field)->type() == MYSQL_TYPE_BLOB || 
-          (*reg_field)->real_type() == MYSQL_TYPE_VARCHAR)
-        key_part_info->store_length+= HA_KEY_BLOB_LENGTH;
+        key_part_info->key_part_flag |= HA_NULL_PART;
+      }
+      if ((*reg_field)->type() == MYSQL_TYPE_BLOB ||
+          (*reg_field)->real_type() == MYSQL_TYPE_VARCHAR ||
+          (*reg_field)->type() == MYSQL_TYPE_GEOMETRY)
+      {
+        if ((*reg_field)->type() == MYSQL_TYPE_BLOB ||
+            (*reg_field)->type() == MYSQL_TYPE_GEOMETRY)
+          key_part_info->key_part_flag|= HA_BLOB_PART;
+        else
+          key_part_info->key_part_flag|= HA_VAR_LENGTH_PART;
+
+        key_part_info->store_length+=HA_KEY_BLOB_LENGTH;
+      }
 
       keyinfo->key_length+= key_part_info->store_length;