Fixed LP bug #826279.

When the WHERE/HAVING condition of a subquery has been transformed
by the optimizer the pointer stored the 'where'/'having' field 
of the SELECT_LEX structure used for the subquery must be updated
accordingly. Otherwise the pointer may refer to an invalid item.
This can lead to the reported assertion failure for some queries
with correlated subqueries   

mysql-test/r/subselect.result

@@ -5338,4 +5338,29 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
 2	DEPENDENT SUBQUERY	t2	range	f1_key	f1_key	4	NULL	6	Range checked for each record (index map: 0x1); Using temporary
 DROP TABLE t1,t2;
+#
+# LP bug #826279: assertion failure with GROUP BY a result of subquery
+#
+CREATE TABLE t1 (a int);
+INSERT INTO t1 VALUES (0), (0);
+CREATE TABLE t2 (a int, b int, c int);
+INSERT INTO t2 VALUES (10,7,0), (0,7,0);
+CREATE TABLE t3 (a int, b int);
+INSERT INTO t3 VALUES (10,7), (0,7);
+SELECT SUM(DISTINCT b),
+(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+7	NULL
+SELECT SUM(DISTINCT b), 
+(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+7	NULL
+7	10
+DROP TABLE t1,t2,t3;
 set optimizer_switch=@subselect_tmp;

mysql-test/r/subselect_no_mat.result

@@ -5343,6 +5343,31 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
 2	DEPENDENT SUBQUERY	t2	range	f1_key	f1_key	4	NULL	6	Range checked for each record (index map: 0x1); Using temporary
 DROP TABLE t1,t2;
+#
+# LP bug #826279: assertion failure with GROUP BY a result of subquery
+#
+CREATE TABLE t1 (a int);
+INSERT INTO t1 VALUES (0), (0);
+CREATE TABLE t2 (a int, b int, c int);
+INSERT INTO t2 VALUES (10,7,0), (0,7,0);
+CREATE TABLE t3 (a int, b int);
+INSERT INTO t3 VALUES (10,7), (0,7);
+SELECT SUM(DISTINCT b),
+(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+7	NULL
+SELECT SUM(DISTINCT b), 
+(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+7	NULL
+7	10
+DROP TABLE t1,t2,t3;
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
 select @@optimizer_switch like '%materialization=on%';

mysql-test/r/subselect_no_opts.result

@@ -5339,5 +5339,30 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
 2	DEPENDENT SUBQUERY	t2	range	f1_key	f1_key	4	NULL	6	Range checked for each record (index map: 0x1); Using temporary
 DROP TABLE t1,t2;
+#
+# LP bug #826279: assertion failure with GROUP BY a result of subquery
+#
+CREATE TABLE t1 (a int);
+INSERT INTO t1 VALUES (0), (0);
+CREATE TABLE t2 (a int, b int, c int);
+INSERT INTO t2 VALUES (10,7,0), (0,7,0);
+CREATE TABLE t3 (a int, b int);
+INSERT INTO t3 VALUES (10,7), (0,7);
+SELECT SUM(DISTINCT b),
+(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+7	NULL
+SELECT SUM(DISTINCT b), 
+(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+7	NULL
+7	10
+DROP TABLE t1,t2,t3;
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;

mysql-test/r/subselect_no_semijoin.result

@@ -5339,5 +5339,30 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
 2	DEPENDENT SUBQUERY	t2	range	f1_key	f1_key	4	NULL	6	Range checked for each record (index map: 0x1); Using temporary
 DROP TABLE t1,t2;
+#
+# LP bug #826279: assertion failure with GROUP BY a result of subquery
+#
+CREATE TABLE t1 (a int);
+INSERT INTO t1 VALUES (0), (0);
+CREATE TABLE t2 (a int, b int, c int);
+INSERT INTO t2 VALUES (10,7,0), (0,7,0);
+CREATE TABLE t3 (a int, b int);
+INSERT INTO t3 VALUES (10,7), (0,7);
+SELECT SUM(DISTINCT b),
+(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+7	NULL
+SELECT SUM(DISTINCT b), 
+(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+7	NULL
+7	10
+DROP TABLE t1,t2,t3;
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;

mysql-test/r/subselect_scache.result

@@ -5342,6 +5342,31 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
 2	DEPENDENT SUBQUERY	t2	range	f1_key	f1_key	4	NULL	6	Range checked for each record (index map: 0x1); Using temporary
 DROP TABLE t1,t2;
+#
+# LP bug #826279: assertion failure with GROUP BY a result of subquery
+#
+CREATE TABLE t1 (a int);
+INSERT INTO t1 VALUES (0), (0);
+CREATE TABLE t2 (a int, b int, c int);
+INSERT INTO t2 VALUES (10,7,0), (0,7,0);
+CREATE TABLE t3 (a int, b int);
+INSERT INTO t3 VALUES (10,7), (0,7);
+SELECT SUM(DISTINCT b),
+(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+WHERE t.a != 0 AND t2.a != 0)
+7	NULL
+SELECT SUM(DISTINCT b), 
+(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+SUM(DISTINCT b)	(SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+7	NULL
+7	10
+DROP TABLE t1,t2,t3;
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
 select @@optimizer_switch like '%subquery_cache=on%';

mysql-test/t/subselect.test

@@ -4590,4 +4590,30 @@ eval explain $query;
 
 DROP TABLE t1,t2;
 
+--echo #
+--echo # LP bug #826279: assertion failure with GROUP BY a result of subquery
+--echo #
+
+CREATE TABLE t1 (a int);
+INSERT INTO t1 VALUES (0), (0);
+
+CREATE TABLE t2 (a int, b int, c int);
+INSERT INTO t2 VALUES (10,7,0), (0,7,0);
+
+CREATE TABLE t3 (a int, b int);
+INSERT INTO t3 VALUES (10,7), (0,7);
+
+SELECT SUM(DISTINCT b),
+       (SELECT t2.a FROM t1 JOIN t2 ON t2.c != 0
+          WHERE t.a != 0 AND t2.a != 0)
+  FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+
+SELECT SUM(DISTINCT b), 
+       (SELECT t2.a FROM t1,t2 WHERE t.a != 0 or 1=2 LIMIT 1)
+  FROM (SELECT * FROM t3) AS t
+GROUP BY 2;
+
+DROP TABLE t1,t2,t3;
+
 set optimizer_switch=@subselect_tmp;

sql/sql_select.cc

@@ -965,13 +965,16 @@ JOIN::optimize()
 
     sel->prep_where= conds ? conds->copy_andor_structure(thd) : 0;
 
+    sel->where= conds;
+
     if (arena)
       thd->restore_active_arena(arena, &backup);
   }
   
   inject_jtbm_conds(this, join_list, &conds);
 
-  conds= optimize_cond(this, conds, join_list, &cond_value, &cond_equal);   
+  conds= optimize_cond(this, conds, join_list, &cond_value, &cond_equal);
+     
   if (thd->is_error())
   {
     error= 1;
@@ -988,10 +991,17 @@ JOIN::optimize()
       DBUG_RETURN(1);
     }
     if (select_lex->where)
+    {
       select_lex->cond_value= cond_value;
+      if (sel->where != conds && cond_value == Item::COND_OK)
+        thd->change_item_tree(&sel->where, conds);
+    }  
     if (select_lex->having)
+    {
       select_lex->having_value= having_value;
-
+      if (sel->having != having && having_value == Item::COND_OK)
+        thd->change_item_tree(&sel->having, having);    
+    }
     if (cond_value == Item::COND_FALSE || having_value == Item::COND_FALSE || 
         (!unit->select_limit_cnt && !(select_options & OPTION_FOUND_ROWS)))
     {						/* Impossible cond */