merging

mysql-test/r/func_in.result

+select 1 in (1,2,3);
+1 in (1,2,3)
+1
+select 10 in (1,2,3);
+10 in (1,2,3)
+0
+select NULL in (1,2,3);
+NULL in (1,2,3)
+NULL
+select 1 in (1,NULL,3);
+1 in (1,NULL,3)
+1
+select 3 in (1,NULL,3);
+3 in (1,NULL,3)
+1
+select 10 in (1,NULL,3);
+10 in (1,NULL,3)
+NULL
+select 1.5 in (1.5,2.5,3.5);
+1.5 in (1.5,2.5,3.5)
+1
+select 10.5 in (1.5,2.5,3.5);
+10.5 in (1.5,2.5,3.5)
+0
+select NULL in (1.5,2.5,3.5);
+NULL in (1.5,2.5,3.5)
+NULL
+select 1.5 in (1.5,NULL,3.5);
+1.5 in (1.5,NULL,3.5)
+1
+select 3.5 in (1.5,NULL,3.5);
+3.5 in (1.5,NULL,3.5)
+1
+select 10.5 in (1.5,NULL,3.5);
+10.5 in (1.5,NULL,3.5)
+NULL
 drop table if exists t1;
+CREATE TABLE t1 (a int, b int, c int);
+insert into t1 values (1,2,3), (1,NULL,3);
+select 1 in (a,b,c) from t1;
+1 in (a,b,c)
+1
+1
+select 3 in (a,b,c) from t1;
+3 in (a,b,c)
+1
+1
+select 10 in (a,b,c) from t1;
+10 in (a,b,c)
+0
+NULL
+select NULL in (a,b,c) from t1;
+NULL in (a,b,c)
+NULL
+NULL
+drop table t1;
+CREATE TABLE t1 (a float, b float, c float);
+insert into t1 values (1.5,2.5,3.5), (1.5,NULL,3.5);
+select 1.5 in (a,b,c) from t1;
+1.5 in (a,b,c)
+1
+1
+select 3.5 in (a,b,c) from t1;
+3.5 in (a,b,c)
+1
+1
+select 10.5 in (a,b,c) from t1;
+10.5 in (a,b,c)
+0
+NULL
+drop table t1;
+CREATE TABLE t1 (a varchar(10), b varchar(10), c varchar(10));
+insert into t1 values ('A','BC','EFD'), ('A',NULL,'EFD');
+select 'A' in (a,b,c) from t1;
+'A' in (a,b,c)
+1
+1
+select 'EFD' in (a,b,c) from t1;
+'EFD' in (a,b,c)
+1
+1
+select 'XSFGGHF' in (a,b,c) from t1;
+'XSFGGHF' in (a,b,c)
+0
+NULL
+drop table t1;
 CREATE TABLE t1 (field char(1));
 INSERT INTO t1 VALUES ('A'),(NULL);
 SELECT * from t1 WHERE field IN (NULL);
 field
 SELECT * from t1 WHERE field NOT IN (NULL);
 field
-A
 SELECT * from t1 where field = field;
 field
 A
@@ -16,6 +100,7 @@ NULL
 DELETE FROM t1 WHERE field NOT IN (NULL);
 SELECT * FROM t1;
 field
+A
 NULL
 drop table t1;
 create table t1 (id int(10) primary key);

mysql-test/r/subselect.result

@@ -598,3 +598,105 @@ INSERT INTO t1 values (1),(1);
 UPDATE t SET id=(SELECT * FROM t1);
 Subselect returns more than 1 record
 drop table t;
+create table t (a int);
+insert into t values (1),(2),(3);
+select 1 IN (SELECT * from t);
+1 IN (SELECT * from t)
+1
+select 10 IN (SELECT * from t);
+10 IN (SELECT * from t)
+0
+select NULL IN (SELECT * from t);
+NULL IN (SELECT * from t)
+NULL
+update t set a=NULL where a=2;
+select 1 IN (SELECT * from t);
+1 IN (SELECT * from t)
+1
+select 3 IN (SELECT * from t);
+3 IN (SELECT * from t)
+1
+select 10 IN (SELECT * from t);
+10 IN (SELECT * from t)
+NULL
+select 1 > ALL (SELECT * from t);
+1 > ALL (SELECT * from t)
+0
+select 10 > ALL (SELECT * from t);
+10 > ALL (SELECT * from t)
+NULL
+select 1 > ANY (SELECT * from t);
+1 > ANY (SELECT * from t)
+NULL
+select 10 > ANY (SELECT * from t);
+10 > ANY (SELECT * from t)
+1
+drop table t;
+create table t (a varchar(20));
+insert into t values ('A'),('BC'),('DEF');
+select 'A' IN (SELECT * from t);
+'A' IN (SELECT * from t)
+1
+select 'XYZS' IN (SELECT * from t);
+'XYZS' IN (SELECT * from t)
+0
+select NULL IN (SELECT * from t);
+NULL IN (SELECT * from t)
+NULL
+update t set a=NULL where a='BC';
+select 'A' IN (SELECT * from t);
+'A' IN (SELECT * from t)
+1
+select 'DEF' IN (SELECT * from t);
+'DEF' IN (SELECT * from t)
+1
+select 'XYZS' IN (SELECT * from t);
+'XYZS' IN (SELECT * from t)
+NULL
+select 'A' > ALL (SELECT * from t);
+'A' > ALL (SELECT * from t)
+0
+select 'XYZS' > ALL (SELECT * from t);
+'XYZS' > ALL (SELECT * from t)
+NULL
+select 'A' > ANY (SELECT * from t);
+'A' > ANY (SELECT * from t)
+NULL
+select 'XYZS' > ANY (SELECT * from t);
+'XYZS' > ANY (SELECT * from t)
+1
+drop table t;
+create table t (a float);
+insert into t values (1.5),(2.5),(3.5);
+select 1.5 IN (SELECT * from t);
+1.5 IN (SELECT * from t)
+1
+select 10.5 IN (SELECT * from t);
+10.5 IN (SELECT * from t)
+0
+select NULL IN (SELECT * from t);
+NULL IN (SELECT * from t)
+NULL
+update t set a=NULL where a=2.5;
+select 1.5 IN (SELECT * from t);
+1.5 IN (SELECT * from t)
+1
+select 3.5 IN (SELECT * from t);
+3.5 IN (SELECT * from t)
+1
+select 10.5 IN (SELECT * from t);
+10.5 IN (SELECT * from t)
+NULL
+select 1.5 > ALL (SELECT * from t);
+1.5 > ALL (SELECT * from t)
+0
+select 10.5 > ALL (SELECT * from t);
+10.5 > ALL (SELECT * from t)
+NULL
+select 1.5 > ANY (SELECT * from t);
+1.5 > ANY (SELECT * from t)
+NULL
+select 10.5 > ANY (SELECT * from t);
+10.5 > ANY (SELECT * from t)
+1
+drop table t;

mysql-test/t/func_in.test

@@ -2,7 +2,39 @@
 # test of IN (NULL)
 #
 
+select 1 in (1,2,3);
+select 10 in (1,2,3);
+select NULL in (1,2,3);
+select 1 in (1,NULL,3);
+select 3 in (1,NULL,3);
+select 10 in (1,NULL,3);
+select 1.5 in (1.5,2.5,3.5);
+select 10.5 in (1.5,2.5,3.5);
+select NULL in (1.5,2.5,3.5);
+select 1.5 in (1.5,NULL,3.5);
+select 3.5 in (1.5,NULL,3.5);
+select 10.5 in (1.5,NULL,3.5);
 drop table if exists t1;
+CREATE TABLE t1 (a int, b int, c int);
+insert into t1 values (1,2,3), (1,NULL,3);
+select 1 in (a,b,c) from t1;
+select 3 in (a,b,c) from t1;
+select 10 in (a,b,c) from t1;
+select NULL in (a,b,c) from t1;
+drop table t1;
+CREATE TABLE t1 (a float, b float, c float);
+insert into t1 values (1.5,2.5,3.5), (1.5,NULL,3.5);
+select 1.5 in (a,b,c) from t1;
+select 3.5 in (a,b,c) from t1;
+select 10.5 in (a,b,c) from t1;
+drop table t1;
+CREATE TABLE t1 (a varchar(10), b varchar(10), c varchar(10));
+insert into t1 values ('A','BC','EFD'), ('A',NULL,'EFD');
+select 'A' in (a,b,c) from t1;
+select 'EFD' in (a,b,c) from t1;
+select 'XSFGGHF' in (a,b,c) from t1;
+drop table t1;
+
 CREATE TABLE t1 (field char(1));
 INSERT INTO t1 VALUES ('A'),(NULL);
 SELECT * from t1 WHERE field IN (NULL);

mysql-test/t/subselect.test

@@ -362,3 +362,48 @@ INSERT INTO t1 values (1),(1);
 -- error 1240
 UPDATE t SET id=(SELECT * FROM t1);
 drop table t;
+
+
+#NULL test
+create table t (a int);
+insert into t values (1),(2),(3);
+select 1 IN (SELECT * from t);
+select 10 IN (SELECT * from t);
+select NULL IN (SELECT * from t);
+update t set a=NULL where a=2;
+select 1 IN (SELECT * from t);
+select 3 IN (SELECT * from t);
+select 10 IN (SELECT * from t);
+select 1 > ALL (SELECT * from t);
+select 10 > ALL (SELECT * from t);
+select 1 > ANY (SELECT * from t);
+select 10 > ANY (SELECT * from t);
+drop table t;
+create table t (a varchar(20));
+insert into t values ('A'),('BC'),('DEF');
+select 'A' IN (SELECT * from t);
+select 'XYZS' IN (SELECT * from t);
+select NULL IN (SELECT * from t);
+update t set a=NULL where a='BC';
+select 'A' IN (SELECT * from t);
+select 'DEF' IN (SELECT * from t);
+select 'XYZS' IN (SELECT * from t);
+select 'A' > ALL (SELECT * from t);
+select 'XYZS' > ALL (SELECT * from t);
+select 'A' > ANY (SELECT * from t);
+select 'XYZS' > ANY (SELECT * from t);
+drop table t;
+create table t (a float);
+insert into t values (1.5),(2.5),(3.5);
+select 1.5 IN (SELECT * from t);
+select 10.5 IN (SELECT * from t);
+select NULL IN (SELECT * from t);
+update t set a=NULL where a=2.5;
+select 1.5 IN (SELECT * from t);
+select 3.5 IN (SELECT * from t);
+select 10.5 IN (SELECT * from t);
+select 1.5 > ALL (SELECT * from t);
+select 10.5 > ALL (SELECT * from t);
+select 1.5 > ANY (SELECT * from t);
+select 10.5 > ANY (SELECT * from t);
+drop table t;

sql/item.cc

@@ -46,6 +46,12 @@ Item::Item():
   loop_id= 0;
 }
 
+Item_ref_in_optimizer::Item_ref_in_optimizer(Item_in_optimizer *master,
+					     char *table_name_par,
+					     char *field_name_par):
+  Item_ref(master->args, table_name_par, field_name_par), owner(master) {}
+
+
 bool Item::check_loop(uint id)
 {
   DBUG_ENTER("Item::check_loop");
@@ -436,6 +442,20 @@ String *Item_copy_string::val_str(String *str)
   return &str_value;
 }
 
+double Item_ref_in_optimizer::val()
+{
+  return owner->get_cache();
+}
+longlong Item_ref_in_optimizer::val_int()
+{
+  return owner->get_cache_int();
+}
+String* Item_ref_in_optimizer::val_str(String* s)
+{
+  return owner->get_cache_str(s);
+}
+
+
 /*
   Functions to convert item to field (for send_fields)
 */
@@ -511,10 +531,31 @@ bool Item_asterisk_remover::fix_fields(THD *thd,
       res= item->fix_fields(thd, list, &item);
   else
     thd->fatal_error= 1; // no item given => out of memory
-  *ref= item;
   DBUG_RETURN(res);
 }
 
+double Item_ref_null_helper::val()
+{
+  double tmp= (*ref)->val_result();
+  owner->was_null|= null_value= (*ref)->is_null_result();
+  return tmp;
+}
+longlong Item_ref_null_helper::val_int()
+{
+  longlong tmp= (*ref)->val_int_result();
+  owner->was_null|= null_value= (*ref)->is_null_result();
+  return tmp;
+}
+String* Item_ref_null_helper::val_str(String* s)
+{
+  String* tmp= (*ref)->str_result(s);
+  owner->was_null|= null_value= (*ref)->is_null_result();
+  return tmp;
+}
+bool Item_ref_null_helper::get_date(TIME *ltime, bool fuzzydate)
+{  
+  return (owner->was_null|= null_value= (*ref)->get_date(ltime, fuzzydate));
+}
 
 bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
 {

sql/item.h

@@ -122,6 +122,18 @@ public:
   String* val_str(String* s)     { return item->val_str(s); }
   void make_field(Send_field* f) { item->make_field(f); }
   bool check_cols(uint col)      { return item->check_cols(col); }
+  bool eq(const Item *item, bool binary_cmp) const
+  { return item->eq(item, binary_cmp); }
+  bool is_null() { return item->is_null_result(); }
+  bool get_date(TIME *ltime, bool fuzzydate)
+  {  
+    return (null_value=item->get_date(ltime, fuzzydate));
+  }
+  bool send(THD *thd, String *tmp)	{ return item->send(thd, tmp); }
+  int  save_in_field(Field *field)	{ return item->save_in_field(field); }
+  void save_org_in_field(Field *field)	{ item->save_org_in_field(field); }
+  enum Item_result result_type () const { return item->result_type(); }
+  table_map used_tables() const		{ return item->used_tables(); }  
 };
 
 
@@ -138,19 +150,6 @@ public:
   bool fix_fields(THD *, struct st_table_list *, Item ** ref);
 };
 
-/*
-  To resolve '*' field moved to condition
-*/
-class Item_asterisk_remover :public Item_wrapper
-{
-public:
-  Item_asterisk_remover(Item *it)
-  {
-    item= it;
-  }
-  bool fix_fields(THD *, struct st_table_list *, Item ** ref);
-};
-
 class st_select_lex;
 class Item_ident :public Item
 {
@@ -384,9 +383,13 @@ public:
   enum Item_result result_type () const { return STRING_RESULT; }
   bool basic_const_item() const { return 1; }
   bool eq(const Item *item, bool binary_cmp) const;
-  Item *new_item() { return new Item_string(name,str_value.ptr(),max_length,default_charset_info); }
+  Item *new_item() 
+  {
+    return new Item_string(name, str_value.ptr(), max_length,
+			   default_charset_info);
+  }
   String *const_string() { return &str_value; }
-  inline void append(char *str,uint length) { str_value.append(str,length); }
+  inline void append(char *str, uint length) { str_value.append(str, length); }
   void print(String *str);
 };
 
@@ -505,6 +508,54 @@ public:
   bool check_loop(uint id);
 };
 
+class Item_in_subselect;
+class Item_ref_null_helper: public Item_ref
+{
+protected:
+  Item_in_subselect* owner;
+public:
+  Item_ref_null_helper(Item_in_subselect* master, Item **item,
+		       char *table_name_par,char *field_name_par):
+    Item_ref(item, table_name_par, field_name_par), owner(master) {}
+  double val();
+  longlong val_int();
+  String* val_str(String* s);
+  bool get_date(TIME *ltime, bool fuzzydate);
+};
+
+/*
+  To resolve '*' field moved to condition
+  and register NULL values
+*/
+class Item_asterisk_remover :public Item_ref_null_helper
+{
+  Item *item;
+public:
+  Item_asterisk_remover(Item_in_subselect *master, Item *it,
+			char *table, char *field):
+    Item_ref_null_helper(master, &item, table, field),
+    item(it) 
+  {}
+  bool fix_fields(THD *, struct st_table_list *, Item ** ref);
+};
+
+class Item_in_optimizer;
+class Item_ref_in_optimizer: public Item_ref
+{
+protected:
+  Item_in_optimizer* owner;
+public:
+  Item_ref_in_optimizer(Item_in_optimizer* master,
+			char *table_name_par,char *field_name_par);
+  double val();
+  longlong val_int();
+  String* val_str(String* s);
+  bool fix_fields(THD *, struct st_table_list *, Item ** ref)
+  {
+    fixed= 1;
+    return 0;
+  }
+};
 
 /*
   The following class is used to optimize comparing of date columns

sql/item_cmpfunc.cc

@@ -263,6 +263,61 @@ int Arg_comparator::compare_e_row()
   return 1;
 }
 
+longlong Item_in_optimizer::val_int()
+{
+  int_cache_ok= 1;
+  flt_cache_ok= 0;
+  str_cache_ok= 0;
+  int_cache= args[0]->val_int_result();
+  if (args[0]->is_null_result())
+  {
+    null_value= 1;
+    return 0;
+  }
+  longlong tmp= args[1]->val_int_result();
+  null_value= args[1]->is_null_result();
+  return tmp;
+}
+
+longlong Item_in_optimizer::get_cache_int()
+{
+  if (!int_cache_ok)
+  {
+    int_cache_ok= 1;
+    flt_cache_ok= 0;
+    str_cache_ok= 0;
+    int_cache= args[0]->val_int_result();
+    null_value= args[0]->is_null_result();
+  }
+  return int_cache;
+}
+
+double Item_in_optimizer::get_cache()
+{
+  if (!flt_cache_ok)
+  {
+    int_cache_ok= 0;
+    flt_cache_ok= 1;
+    str_cache_ok= 0;
+    flt_cache= args[0]->val_result();
+    null_value= args[0]->is_null_result();
+  }
+  return flt_cache;
+}
+
+String *Item_in_optimizer::get_cache_str(String *s)
+{
+  if (!str_cache_ok)
+  {
+    int_cache_ok= 0;
+    flt_cache_ok= 0;
+    str_cache_ok= 1;
+    str_cache_buff.set(buffer, sizeof(buffer), s->charset());
+    str_cache= args[0]->str_result(&str_cache_buff);
+    null_value= args[0]->is_null_result();
+  }
+  return str_cache;
+}
 
 longlong Item_func_eq::val_int()
 {
@@ -1106,6 +1161,8 @@ void Item_func_in::fix_length_and_dec()
       array->set(j,args[i]);
       if (!args[i]->null_value)			// Skip NULL values
 	j++;
+      else
+	have_null= 1;
     }
     if ((array->used_count=j))
       array->sort();
@@ -1152,17 +1209,20 @@ longlong Item_func_in::val_int()
   if (array)
   {
     int tmp=array->find(item);
-    null_value=item->null_value;
+    null_value=item->null_value || (!tmp && have_null);
     return tmp;
   }
   in_item->store_value(item);
   if ((null_value=item->null_value))
     return 0;
+  have_null= 0;
   for (uint i=0 ; i < arg_count ; i++)
   {
     if (!in_item->cmp(args[i]) && !args[i]->null_value)
       return 1;					// Would maybe be nice with i ?
+    have_null|= args[i]->null_value;
   }
+  null_value= have_null;
   return 0;
 }
 

sql/item_cmpfunc.h

@@ -87,6 +87,27 @@ public:
   void fix_length_and_dec() { decimals=0; max_length=1; }
 };
 
+class Item_in_optimizer: public Item_bool_func
+{
+protected:
+  char buffer[80];
+  longlong int_cache;
+  double flt_cache;
+  String str_cache_buff, *str_cache;
+  bool int_cache_ok, flt_cache_ok, str_cache_ok;
+public:
+  Item_in_optimizer(Item *a,Item *b):
+    Item_bool_func(a,b), int_cache_ok(0), flt_cache_ok(0), str_cache_ok(0) {}
+  bool is_null() { return test(args[0]->is_null() || args[1]->is_null()); }
+  longlong val_int();
+
+  double get_cache();
+  longlong get_cache_int();
+  String *get_cache_str(String *s);
+
+  friend class Item_ref_in_optimizer;
+};
+
 class Item_bool_func2 :public Item_int_func
 {						/* Bool with 2 string args */
 protected:
@@ -488,9 +509,10 @@ class Item_func_in :public Item_int_func
   Item *item;
   in_vector *array;
   cmp_item *in_item;
+  bool have_null;
  public:
   Item_func_in(Item *a,List<Item> &list)
-    :Item_int_func(list),item(a),array(0),in_item(0) {}
+    :Item_int_func(list), item(a), array(0), in_item(0), have_null(0) {}
   longlong val_int();
   bool fix_fields(THD *thd, struct st_table_list *tlist, Item **ref)
   {

sql/item_subselect.cc

@@ -33,9 +33,10 @@ SUBSELECT TODO:
 #include "sql_select.h"
 
 Item_subselect::Item_subselect():
-  Item_result_field(), engine_owner(1), value_assigned(0), substitution(0)
+  Item_result_field(), engine_owner(1), value_assigned(0), substitution(0),
+  have_to_be_excluded(0)
 {
-  assign_null();
+  reset();
   /*
     item value is NULL if select_subselect not changed this value 
     (i.e. some rows will be found returned)
@@ -93,8 +94,10 @@ bool Item_subselect::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
   {
     (*ref)= substitution;
     substitution->name= name;
-    engine->exclude();
-    return substitution->fix_fields(thd, tables, ref);
+    if (have_to_be_excluded)
+      engine->exclude();
+    substitution= 0;
+    return (*ref)->fix_fields(thd, tables, ref);
   }
 
   char const *save_where= thd->where;
@@ -159,7 +162,7 @@ double Item_singleval_subselect::val ()
 {
   if (engine->exec())
   {
-    assign_null();
+    reset();
     return 0;
   }
   return real_value;
@@ -169,7 +172,7 @@ longlong Item_singleval_subselect::val_int ()
 {
   if (engine->exec())
   {
-    assign_null();
+    reset();
     return 0;
   }
   return int_value;
@@ -179,7 +182,7 @@ String *Item_singleval_subselect::val_str (String *str)
 {
   if (engine->exec() || null_value)
   {
-    assign_null();
+    reset();
     return 0;
   }
   return &string_value;
@@ -208,9 +211,8 @@ Item_in_subselect::Item_in_subselect(THD *thd, Item * left_exp,
   left_expr= left_exp;
   init(thd, select_lex, new select_exists_subselect(this));
   max_columns= UINT_MAX;
-  null_value= 0; //can't be NULL
-  maybe_null= 0; //can't be NULL
-  value= 0;
+  maybe_null= 1;
+  reset();
   // We need only 1 row to determinate existence
   select_lex->master_unit()->global_parameters->select_limit= 1;
   DBUG_VOID_RETURN;
@@ -226,9 +228,7 @@ Item_allany_subselect::Item_allany_subselect(THD *thd, Item * left_exp,
   func= f;
   init(thd, select_lex, new select_exists_subselect(this));
   max_columns= UINT_MAX;
-  null_value= 0; //can't be NULL
-  maybe_null= 0; //can't be NULL
-  value= 0;
+  reset();
   // We need only 1 row to determinate existence
   select_lex->master_unit()->global_parameters->select_limit= 1;
   DBUG_VOID_RETURN;
@@ -237,14 +237,15 @@ Item_allany_subselect::Item_allany_subselect(THD *thd, Item * left_exp,
 
 void Item_exists_subselect::fix_length_and_dec()
 {
-  max_length= 1;
+   decimals=0;
+   max_length= 1;
 }
 
 double Item_exists_subselect::val () 
 {
   if (engine->exec())
   {
-    assign_null();
+    reset();
     return 0;
   }
   return (double) value;
@@ -254,7 +255,7 @@ longlong Item_exists_subselect::val_int ()
 {
   if (engine->exec())
   {
-    assign_null();
+    reset();
     return 0;
   }
   return value;
@@ -264,7 +265,50 @@ String *Item_exists_subselect::val_str(String *str)
 {
   if (engine->exec())
   {
-    assign_null();
+    reset();
+    return 0;
+  }
+  str->set(value,thd_charset());
+  return str;
+}
+
+double Item_in_subselect::val () 
+{
+  if (engine->exec())
+  {
+    reset();
+    null_value= 1;
+    return 0;
+  }
+  if (was_null && !value)
+    null_value= 1;
+  return (double) value;
+}
+
+longlong Item_in_subselect::val_int () 
+{
+  if (engine->exec())
+  {
+    reset();
+    null_value= 1;
+    return 0;
+  }
+  if (was_null && !value)
+    null_value= 1;
+  return value;
+}
+
+String *Item_in_subselect::val_str(String *str)
+{
+  if (engine->exec())
+  {
+    reset();
+    null_value= 1;
+    return 0;
+  }
+  if (was_null && !value)
+  {
+    null_value= 1;
     return 0;
   }
   str->set(value,thd_charset());
@@ -288,8 +332,23 @@ void Item_in_subselect::single_value_transformer(st_select_lex *select_lex,
 						 compare_func_creator func)
 {
   DBUG_ENTER("Item_in_subselect::single_value_transformer");
+  Item_in_optimizer *optimizer;
+  substitution= optimizer= new Item_in_optimizer(left_expr, this);
+  if (!optimizer)
+  {
+    current_thd->fatal_error= 1;
+    DBUG_VOID_RETURN;
+  }
+  /*
+    As far as  Item_ref_in_optimizer do not substitude itself on fix_fields
+    we can use same item for all selects.
+  */
+  Item *expr= new Item_ref_in_optimizer(optimizer, (char *)"<no matter>",
+					(char*)"<left expr>");
+  select_lex->master_unit()->dependent= 1;
   for (SELECT_LEX * sl= select_lex; sl; sl= sl->next_select())
   {
+    select_lex->dependent= 1;
     Item *item;
     if (sl->item_list.elements > 1)
     {
@@ -299,14 +358,14 @@ void Item_in_subselect::single_value_transformer(st_select_lex *select_lex,
     else
       item= (Item*) sl->item_list.pop();
 
-    Item *expr= new Item_outer_select_context_saver(left_expr);
-
     if (sl->having || sl->with_sum_func || sl->group_list.first ||
 	sl->order_list.first)
     {
       sl->item_list.push_back(item);
-      item= (*func)(expr, new Item_ref(sl->item_list.head_ref(),
-					    0, (char*)"<result>"));
+      item= (*func)(expr, new Item_ref_null_helper(this,
+						   sl->item_list.head_ref(),
+						   (char *)"<no matter>",
+						   (char*)"<result>"));
       if (sl->having || sl->with_sum_func || sl->group_list.first)
 	if (sl->having)
 	  sl->having= new Item_cond_and(sl->having, item);
@@ -324,7 +383,9 @@ void Item_in_subselect::single_value_transformer(st_select_lex *select_lex,
       sl->item_list.push_back(new Item_int(1));
       if (sl->table_list.elements)
       {
-	item= (*func)(expr, new Item_asterisk_remover(item));
+	item= (*func)(expr, new Item_asterisk_remover(this, item,
+						      (char *)"<no matter>",
+						      (char*)"<result>"));
 	if (sl->where)
 	  sl->where= new Item_cond_and(sl->where, item);
 	else
@@ -340,14 +401,21 @@ void Item_in_subselect::single_value_transformer(st_select_lex *select_lex,
 	}
 	if (select_lex->next_select())
 	{
-	  // it is in union => we should perform it
-	  sl->having= (*func)(expr, item);
+	  /* 
+	     It is in union => we should perform it.
+	     Item_asterisk_remover used only as wrapper to receine NULL value
+	  */
+	  sl->having= (*func)(expr, 
+			      new Item_asterisk_remover(this, item,
+							(char *)"<no matter>",
+							(char*)"<result>"));
 	}
 	else
 	{
 	  // it is single select without tables => possible optimization
 	  item= (*func)(left_expr, item);
 	  substitution= item;
+	  have_to_be_excluded= 1;
 	  THD *thd= current_thd;
 	  if (thd->lex.describe)
 	  {
@@ -489,7 +557,7 @@ int subselect_single_select_engine::exec()
       join->thd->where= save_where;
       DBUG_RETURN(1);
     }
-    item->assign_null();
+    item->reset();
     item->assigned((executed= 0));
   }
   if (!executed)

sql/item_subselect.h

@@ -42,6 +42,8 @@ protected:
   subselect_engine *engine; 
   /* allowed number of columns (1 for single value subqueries) */
   uint max_columns;
+  /* work with 'substitution' */
+  bool have_to_be_excluded;
 
 public:
   Item_subselect();
@@ -65,7 +67,7 @@ public:
 		     select_subselect *result);
 
   ~Item_subselect();
-  virtual void assign_null() 
+  virtual void reset() 
   {
     null_value= 1;
   }
@@ -110,7 +112,7 @@ public:
     decimals= item->decimals;
     res_type= item->res_type;
   }
-  virtual void assign_null() 
+  virtual void reset() 
   {
     null_value= 1;
     int_value= 0;
@@ -144,7 +146,7 @@ public:
   }
   Item_exists_subselect(): Item_subselect() {}
 
-  virtual void assign_null() 
+  virtual void reset() 
   {
     value= 0;
   }
@@ -155,6 +157,7 @@ public:
   double val();
   String *val_str(String*);
   void fix_length_and_dec();
+
   friend class select_exists_subselect;
 };
 
@@ -164,14 +167,26 @@ class Item_in_subselect :public Item_exists_subselect
 {
 protected:
   Item * left_expr;
-
+  bool was_null;
 public:
   Item_in_subselect(THD *thd, Item * left_expr, st_select_lex *select_lex);
   Item_in_subselect(Item_in_subselect *item);
   Item_in_subselect(): Item_exists_subselect() {}
+  void reset() 
+  {
+    value= 0;
+    null_value= 0;
+    was_null= 0;
+  }
   virtual void select_transformer(st_select_lex *select_lex);
   void single_value_transformer(st_select_lex *select_lex,
 				Item *left_expr, compare_func_creator func);
+  longlong val_int();
+  double val();
+  String *val_str(String*);
+
+  friend class Item_asterisk_remover;
+  friend class Item_ref_null_helper;
 };
 
 /* ALL/ANY/SOME subselect */

sql/sql_class.cc

@@ -935,7 +935,7 @@ bool select_singleval_subselect::send_data(List<Item> &items)
   it->real_value= val_item->val_result();
   if ((it->null_value= val_item->is_null_result()))
   {
-    it->assign_null();
+    it->reset();
   } 
   else 
   {

sql/sql_union.cc

@@ -216,7 +216,7 @@ int st_select_lex_unit::exec()
     if (optimized && item && item->assigned())
     {
       item->assigned(0); // We will reinit & rexecute unit
-      item->assign_null();
+      item->reset();
       table->file->delete_all_rows();
     }
     for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())