MDEV-12713 Define virtual type_handler() for all Item classes

sql/item.h

@@ -729,10 +729,7 @@ class Item: public Value_source,
   }
   virtual bool eq(const Item *, bool binary_cmp) const;
   virtual enum_field_types field_type() const= 0;
-  virtual const Type_handler *type_handler() const
-  {
-    return Type_handler::get_handler_by_field_type(field_type());
-  }
+  virtual const Type_handler *type_handler() const= 0;
   const Type_handler *type_handler_for_comparison() const
   {
     return type_handler()->type_handler_for_comparison();
@@ -759,6 +756,10 @@ class Item: public Value_source,
   {
     return Type_handler::string_type_handler(max_length)->field_type();
   }
+  const Type_handler *string_type_handler() const
+  {
+    return Type_handler::string_type_handler(max_length);
+  }
   /*
     Calculate the maximum length of an expression.
     This method is used in data type aggregation for UNION, e.g.:
@@ -2395,6 +2396,7 @@ class Item_case_expr :public Item_sp_variable
   inline enum Type type() const;
   inline Item_result result_type() const;
   enum_field_types field_type() const { return this_item()->field_type(); }
+  const Type_handler *type_handler() const { return this_item()->type_handler(); }
 
 public:
   /*
@@ -2456,6 +2458,11 @@ class Item_name_const : public Item
   bool is_null();
   virtual void print(String *str, enum_query_type query_type);
 
+  const Type_handler *type_handler() const
+  {
+    return value_item->type_handler();
+  }
+
   enum_field_types field_type() const
   {
     return value_item->field_type();
@@ -2617,6 +2624,11 @@ class Item_ident_for_show :public Item
   my_decimal *val_decimal(my_decimal *dec) { return field->val_decimal(dec); }
   void make_field(THD *thd, Send_field *tmp_field);
   enum_field_types field_type() const { return field->type(); }
+  const Type_handler *type_handler() const
+  {
+    const Type_handler *handler= field->type_handler();
+    return handler->type_handler_for_item_field();
+  }
   Item* get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_ident_for_show>(thd, mem_root, this); }
 };
@@ -2916,6 +2928,7 @@ class Item_null :public Item_basic_constant
   bool send(Protocol *protocol, st_value *buffer);
   enum Item_result result_type () const { return STRING_RESULT; }
   enum_field_types field_type() const   { return MYSQL_TYPE_NULL; }
+  const Type_handler *type_handler() const { return &type_handler_null; }
   bool basic_const_item() const { return 1; }
   Item *clone_item(THD *thd);
   bool is_null() { return 1; }
@@ -3332,6 +3345,7 @@ class Item_decimal :public Item_num
   enum Type type() const { return DECIMAL_ITEM; }
   enum Item_result result_type () const { return DECIMAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; }
+  const Type_handler *type_handler() const { return &type_handler_newdecimal; }
   longlong val_int();
   double val_real();
   String *val_str(String*);
@@ -3373,6 +3387,7 @@ class Item_float :public Item_num
   int save_in_field(Field *field, bool no_conversions);
   enum Type type() const { return REAL_ITEM; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
   double val_real() { DBUG_ASSERT(fixed == 1); return value; }
   longlong val_int()
   {
@@ -3513,6 +3528,7 @@ class Item_string :public Item_basic_constant
   int save_in_field(Field *field, bool no_conversions);
   enum Item_result result_type () const { return STRING_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; }
+  const Type_handler *type_handler() const { return &type_handler_varchar; }
   bool basic_const_item() const { return 1; }
   bool eq(const Item *item, bool binary_cmp) const
   {
@@ -3698,6 +3714,10 @@ class Item_return_date_time :public Item_partition_func_safe_string
     date_time_field_type(field_type_arg)
   { decimals= 0; }
   enum_field_types field_type() const { return date_time_field_type; }
+  const Type_handler *type_handler() const
+  {
+    return Type_handler::get_handler_by_field_type(field_type());
+  }
 };
 
 
@@ -3787,6 +3807,7 @@ class Item_hex_constant: public Item_basic_constant
   enum Type type() const { return VARBIN_ITEM; }
   enum Item_result result_type () const { return STRING_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; }
+  const Type_handler *type_handler() const { return &type_handler_varchar; }
   virtual Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs)
   {
     return const_charset_converter(thd, tocs, true);
@@ -3964,6 +3985,7 @@ class Item_date_literal: public Item_temporal_literal
     maybe_null= !ltime->month || !ltime->day;
   }
   enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
+  const Type_handler *type_handler() const { return &type_handler_newdate; }
   void print(String *str, enum_query_type query_type);
   Item *clone_item(THD *thd);
   bool get_date(MYSQL_TIME *res, ulonglong fuzzy_date);
@@ -3985,6 +4007,7 @@ class Item_time_literal: public Item_temporal_literal
     fixed= 1;
   }
   enum_field_types field_type() const { return MYSQL_TYPE_TIME; }
+  const Type_handler *type_handler() const { return &type_handler_time2; }
   void print(String *str, enum_query_type query_type);
   Item *clone_item(THD *thd);
   bool get_date(MYSQL_TIME *res, ulonglong fuzzy_date);
@@ -4008,6 +4031,7 @@ class Item_datetime_literal: public Item_temporal_literal
     maybe_null= !ltime->month || !ltime->day;
   }
   enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
+  const Type_handler *type_handler() const { return &type_handler_datetime2; }
   void print(String *str, enum_query_type query_type);
   Item *clone_item(THD *thd);
   bool get_date(MYSQL_TIME *res, ulonglong fuzzy_date);
@@ -4323,6 +4347,7 @@ class Item_ref :public Item_ident
   { return (*ref)->setup_fast_field_copier(field); }
   enum Item_result result_type () const { return (*ref)->result_type(); }
   enum_field_types field_type() const   { return (*ref)->field_type(); }
+  const Type_handler *type_handler() const { return (*ref)->type_handler(); }
   const Type_handler *real_type_handler() const
   { return (*ref)->real_type_handler(); }
   Field *get_tmp_table_field()
@@ -4618,6 +4643,7 @@ class Item_cache_wrapper :public Item_result_field
     orig_item->fix_after_pullout(new_parent, &orig_item);
   }
   int save_in_field(Field *to, bool no_conversions);
+  const Type_handler *type_handler() const { return orig_item->type_handler(); }
   enum Item_result result_type () const { return orig_item->result_type(); }
   enum_field_types field_type() const   { return orig_item->field_type(); }
   table_map used_tables() const { return orig_item->used_tables(); }
@@ -5011,7 +5037,7 @@ class Item_copy :public Item,
     null_value=maybe_null=item->maybe_null;
     Type_std_attributes::set(item);
     name= item->name;
-    set_handler_by_field_type(item->field_type());
+    set_handler(item->type_handler());
     fixed= item->fixed;
   }
 

sql/item_cmpfunc.h

@@ -1014,7 +1014,7 @@ class Item_func_case_abbreviation2 :public Item_func_case_expression
   void cache_type_info(const Item *source, bool maybe_null_arg)
   {
     Type_std_attributes::set(source);
-    set_handler_by_field_type(source->field_type());
+    set_handler(source->type_handler());
     maybe_null= maybe_null_arg;
   }
 
@@ -2767,7 +2767,6 @@ class Item_cond :public Item_bool_func
   Item *transform(THD *thd, Item_transformer transformer, uchar *arg);
   void traverse_cond(Cond_traverser, void *arg, traverse_order order);
   void neg_arguments(THD *thd);
-  enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
   Item* propagate_equal_fields(THD *, const Context &, COND_EQUAL *);
   Item *compile(THD *thd, Item_analyzer analyzer, uchar **arg_p,
                 Item_transformer transformer, uchar *arg_t);

sql/item_func.cc

@@ -5612,7 +5612,7 @@ enum Item_result Item_func_get_system_var::result_type() const
 }
 
 
-enum_field_types Item_func_get_system_var::field_type() const
+const Type_handler *Item_func_get_system_var::type_handler() const
 {
   switch (var->show_type())
   {
@@ -5625,16 +5625,16 @@ enum_field_types Item_func_get_system_var::field_type() const
     case SHOW_ULONG:
     case SHOW_ULONGLONG:
     case SHOW_HA_ROWS:
-      return MYSQL_TYPE_LONGLONG;
+      return &type_handler_longlong;
     case SHOW_CHAR: 
     case SHOW_CHAR_PTR: 
     case SHOW_LEX_STRING:
-      return MYSQL_TYPE_VARCHAR;
+      return &type_handler_varchar;
     case SHOW_DOUBLE:
-      return MYSQL_TYPE_DOUBLE;
+      return &type_handler_double;
     default:
       my_error(ER_VAR_CANT_BE_READ, MYF(0), var->name.str);
-      return MYSQL_TYPE_VARCHAR;              // keep the compiler happy
+      return &type_handler_varchar;              // keep the compiler happy
   }
 }
 
@@ -6458,6 +6458,15 @@ Item_func_sp::field_type() const
   DBUG_RETURN(sp_result_field->type());
 }
 
+const Type_handler *Item_func_sp::type_handler() const
+{
+  DBUG_ENTER("Item_func_sp::type_handler");
+  DBUG_ASSERT(sp_result_field);
+  // This converts ENUM/SET to STRING
+  const Type_handler *handler= sp_result_field->type_handler();
+  DBUG_RETURN(handler->type_handler_for_item_field());
+}
+
 Item_result
 Item_func_sp::result_type() const
 {

sql/item_func.h

@@ -372,6 +372,7 @@ class Item_real_func :public Item_func
     { DBUG_ASSERT(fixed == 1); return (longlong) rint(val_real()); }
   enum Item_result result_type () const { return REAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
   void fix_length_and_dec()
   { decimals= NOT_FIXED_DEC; max_length= float_length(decimals); }
 };
@@ -737,6 +738,7 @@ class Item_int_func :public Item_func
   String *val_str(String*str);
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   void fix_length_and_dec() {}
 };
 
@@ -909,6 +911,7 @@ class Item_decimal_typecast :public Item_func
   my_decimal *val_decimal(my_decimal*);
   enum Item_result result_type () const { return DECIMAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; }
+  const Type_handler *type_handler() const { return &type_handler_newdecimal; }
   void fix_length_and_dec_generic() {}
   void fix_length_and_dec()
   {
@@ -932,7 +935,6 @@ class Item_double_typecast :public Item_real_func
     max_length= (uint32) len;
   }
   double val_real();
-  enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
   void fix_length_and_dec_generic() { maybe_null= 1; }
   void fix_length_and_dec()
   {
@@ -1546,6 +1548,7 @@ class Item_func_rollup_const :public Item_func
   bool const_item() const { return 0; }
   Item_result result_type() const { return args[0]->result_type(); }
   enum_field_types field_type() const { return args[0]->field_type(); }
+  const Type_handler *type_handler() const { return args[0]->type_handler(); }
   void fix_length_and_dec()
   {
     collation= args[0]->collation;
@@ -1953,6 +1956,7 @@ class Item_func_udf_float :public Item_udf_func
   double val_real();
   String *val_str(String *str);
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
   void fix_length_and_dec() { fix_num_length_and_dec(); }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_func_udf_float>(thd, mem_root, this); }
@@ -1972,6 +1976,7 @@ class Item_func_udf_int :public Item_udf_func
   String *val_str(String *str);
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   void fix_length_and_dec() { decimals= 0; max_length= 21; }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_func_udf_int>(thd, mem_root, this); }
@@ -1991,6 +1996,7 @@ class Item_func_udf_decimal :public Item_udf_func
   String *val_str(String *str);
   enum Item_result result_type () const { return DECIMAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; }
+  const Type_handler *type_handler() const { return &type_handler_newdecimal; }
   void fix_length_and_dec() { fix_num_length_and_dec(); }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_func_udf_decimal>(thd, mem_root, this); }
@@ -2031,6 +2037,7 @@ class Item_func_udf_str :public Item_udf_func
   }
   enum Item_result result_type () const { return STRING_RESULT; }
   enum_field_types field_type() const { return string_field_type(); }
+  const Type_handler *type_handler() const { return string_type_handler(); }
   void fix_length_and_dec();
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_func_udf_str>(thd, mem_root, this); }
@@ -2360,6 +2367,7 @@ class Item_user_var_as_out_param :public Item,
   void load_data_print(THD *thd, String *str);
   void load_data_set_null_value(CHARSET_INFO* cs);
   void load_data_set_value(const char *str, uint length, CHARSET_INFO* cs);
+  const Type_handler *type_handler() const { return &type_handler_double; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_user_var_as_out_param>(thd, mem_root, this); }
@@ -2396,7 +2404,11 @@ class Item_func_get_system_var :public Item_func
   bool const_item() const { return true; }
   table_map used_tables() const { return 0; }
   enum Item_result result_type() const;
-  enum_field_types field_type() const;
+  enum_field_types field_type() const
+  {
+    return Item_func_get_system_var::type_handler()->field_type();
+  }
+  const Type_handler *type_handler() const;
   double val_real();
   longlong val_int();
   String* val_str(String*);
@@ -2658,6 +2670,8 @@ class Item_func_sp :public Item_func
 
   enum enum_field_types field_type() const;
 
+  const Type_handler *type_handler() const;
+
   Field *create_field_for_create_select(TABLE *table)
   {
     return result_type() != STRING_RESULT ?
@@ -2843,6 +2857,7 @@ class Item_func_last_value :public Item_func
   const char *func_name() const { return "last_value"; }
   table_map not_null_tables() const { return 0; }
   enum_field_types field_type() const { return last_value->field_type(); }
+  const Type_handler *type_handler() const { return last_value->type_handler(); }
   bool const_item() const { return 0; }
   void evaluate_sideeffects();
   void update_used_tables()

sql/item_geofunc.h

@@ -40,6 +40,7 @@ class Item_geometry_func: public Item_str_func
   Item_geometry_func(THD *thd, List<Item> &list): Item_str_func(thd, list) {}
   void fix_length_and_dec();
   enum_field_types field_type() const  { return MYSQL_TYPE_GEOMETRY; }
+  const Type_handler *type_handler() const { return &type_handler_geometry; }
 };
 
 class Item_func_geometry_from_text: public Item_geometry_func
@@ -101,6 +102,7 @@ class Item_func_as_wkb: public Item_geometry_func
   const char *func_name() const { return "st_aswkb"; }
   String *val_str(String *);
   enum_field_types field_type() const  { return MYSQL_TYPE_LONG_BLOB; }
+  const Type_handler *type_handler() const { return &type_handler_long_blob; }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_func_as_wkb>(thd, mem_root, this); }
 };

sql/item_strfunc.h

@@ -66,6 +66,7 @@ class Item_str_func :public Item_func
   my_decimal *val_decimal(my_decimal *);
   enum Item_result result_type () const { return STRING_RESULT; }
   enum_field_types field_type() const { return string_field_type(); }
+  const Type_handler *type_handler() const { return string_type_handler(); }
   void left_right_max_length();
   bool fix_fields(THD *thd, Item **ref);
   void update_null_value()

sql/item_subselect.h

@@ -398,6 +398,7 @@ class Item_exists_subselect :public Item_subselect
 
   enum Item_result result_type() const { return INT_RESULT;}
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   longlong val_int();
   double val_real();
   String *val_str(String*);

sql/item_sum.h

@@ -750,6 +750,7 @@ class Item_sum_int :public Item_sum_num
   my_decimal *val_decimal(my_decimal *);
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   void fix_length_and_dec()
   { decimals=0; max_length=21; maybe_null=null_value=0; }
 };
@@ -982,6 +983,7 @@ class Item_sum_variance : public Item_sum_num
   Field *create_tmp_field(bool group, TABLE *table);
   enum Item_result result_type () const { return REAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE;}
+  const Type_handler *type_handler() const { return &type_handler_double; }
   void cleanup()
   {
     count= 0;
@@ -1265,6 +1267,7 @@ class Item_avg_field_double :public Item_avg_field
   { }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
   enum Item_result result_type () const { return REAL_RESULT; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
   longlong val_int() { return val_int_from_real(); }
   my_decimal *val_decimal(my_decimal *dec) { return val_decimal_from_real(dec); }
   String *val_str(String *str) { return val_string_from_real(str); }
@@ -1286,6 +1289,7 @@ class Item_avg_field_decimal :public Item_avg_field
   { }
   enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; }
   enum Item_result result_type () const { return DECIMAL_RESULT; }
+  const Type_handler *type_handler() const { return &type_handler_newdecimal; }
   double val_real() { return val_real_from_decimal(); }
   longlong val_int() { return val_int_from_decimal(); }
   String *val_str(String *str) { return val_string_from_decimal(str); }
@@ -1311,6 +1315,7 @@ class Item_variance_field :public Item_sum_field
   { return val_decimal_from_real(dec_buf); }
   bool is_null() { update_null_value(); return null_value; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
   enum Item_result result_type () const { return REAL_RESULT; }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_variance_field>(thd, mem_root, this); }
@@ -1412,6 +1417,7 @@ class Item_sum_udf_float :public Item_udf_sum
   enum Item_result result_type () const { return REAL_RESULT; }
   enum Item_result cmp_type () const { return REAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
   void fix_length_and_dec() { fix_num_length_and_dec(); }
   Item *copy_or_same(THD* thd);
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
@@ -1435,6 +1441,7 @@ class Item_sum_udf_int :public Item_udf_sum
   my_decimal *val_decimal(my_decimal *);
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   void fix_length_and_dec() { decimals=0; max_length=21; }
   Item *copy_or_same(THD* thd);
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
@@ -1477,6 +1484,7 @@ class Item_sum_udf_str :public Item_udf_sum
   my_decimal *val_decimal(my_decimal *dec);
   enum Item_result result_type () const { return STRING_RESULT; }
   enum_field_types field_type() const { return string_field_type(); }
+  const Type_handler *type_handler() const { return string_type_handler(); }
   void fix_length_and_dec();
   Item *copy_or_same(THD* thd);
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
@@ -1499,6 +1507,7 @@ class Item_sum_udf_decimal :public Item_udf_sum
   my_decimal *val_decimal(my_decimal *);
   enum Item_result result_type () const { return DECIMAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; }
+  const Type_handler *type_handler() const { return &type_handler_newdecimal; }
   void fix_length_and_dec() { fix_num_length_and_dec(); }
   Item *copy_or_same(THD* thd);
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
@@ -1650,11 +1659,14 @@ class Item_func_group_concat : public Item_sum
   virtual Item_result result_type () const { return STRING_RESULT; }
   virtual Item_result cmp_type () const { return STRING_RESULT; }
   enum_field_types field_type() const
+  {
+    return Item_func_group_concat::type_handler()->field_type();
+  }
+  const Type_handler *type_handler() const
   {
     if (too_big_for_varchar())
-      return MYSQL_TYPE_BLOB;
-    else
-      return MYSQL_TYPE_VARCHAR;
+      return &type_handler_blob;
+    return &type_handler_varchar;
   }
   void clear();
   bool add();

sql/item_timefunc.h

@@ -157,6 +157,7 @@ class Item_func_month :public Item_func
   const char *func_name() const { return "month"; }
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   void fix_length_and_dec()
   { 
     decimals= 0;
@@ -407,6 +408,7 @@ class Item_func_weekday :public Item_func
   }
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   void fix_length_and_dec()
   {
     decimals= 0;
@@ -432,6 +434,7 @@ class Item_func_dayname :public Item_func_weekday
   String *val_str(String *str);
   enum Item_result result_type () const { return STRING_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; }
+  const Type_handler *type_handler() const { return &type_handler_varchar; }
   void fix_length_and_dec();
   bool check_partition_func_processor(void *int_arg) {return TRUE;}
   bool check_vcol_func_processor(void *arg)
@@ -586,6 +589,7 @@ class Item_datefunc :public Item_temporal_func
   Item_datefunc(THD *thd, Item *a): Item_temporal_func(thd, a) { }
   Item_datefunc(THD *thd, Item *a, Item *b): Item_temporal_func(thd, a, b) { }
   enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
+  const Type_handler *type_handler() const { return &type_handler_newdate; }
   void fix_length_and_dec()
   {
     fix_attributes_date();
@@ -603,6 +607,7 @@ class Item_timefunc :public Item_temporal_func
   Item_timefunc(THD *thd, Item *a, Item *b, Item *c):
     Item_temporal_func(thd, a, b ,c) {}
   enum_field_types field_type() const { return MYSQL_TYPE_TIME; }
+  const Type_handler *type_handler() const { return &type_handler_time2; }
 };
 
 
@@ -614,6 +619,7 @@ class Item_datetimefunc :public Item_temporal_func
   Item_datetimefunc(THD *thd, Item *a, Item *b, Item *c):
     Item_temporal_func(thd, a, b ,c) {}
   enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
+  const Type_handler *type_handler() const { return &type_handler_datetime2; }
 };
 
 
@@ -938,6 +944,10 @@ class Item_extract :public Item_int_func
   Item_extract(THD *thd, interval_type type_arg, Item *a):
     Item_int_func(thd, a), int_type(type_arg) {}
   enum_field_types field_type() const
+  {
+    return Item_extract::type_handler()->field_type();
+  }
+  const Type_handler *type_handler() const
   {
     switch (int_type) {
     case INTERVAL_YEAR:
@@ -957,16 +967,16 @@ class Item_extract :public Item_int_func
     case INTERVAL_SECOND:
     case INTERVAL_MICROSECOND:
     case INTERVAL_SECOND_MICROSECOND:
-      return MYSQL_TYPE_LONG;
+      return &type_handler_long;
     case INTERVAL_DAY_MICROSECOND:
     case INTERVAL_HOUR_MICROSECOND:
     case INTERVAL_MINUTE_MICROSECOND:
-      return MYSQL_TYPE_LONGLONG;
+      return &type_handler_longlong;
     case INTERVAL_LAST:
       break;
     }
     DBUG_ASSERT(0);
-    return MYSQL_TYPE_LONGLONG;
+    return &type_handler_longlong;
   }
   longlong val_int();
   enum Functype functype() const { return EXTRACT_FUNC; }
@@ -1074,6 +1084,7 @@ class Item_date_typecast :public Item_temporal_typecast
   bool get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date);
   const char *cast_type() const { return "date"; }
   enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
+  const Type_handler *type_handler() const { return &type_handler_newdate; }
   void fix_length_and_dec()
   {
     args[0]->type_handler()->Item_date_typecast_fix_length_and_dec(this);
@@ -1092,6 +1103,7 @@ class Item_time_typecast :public Item_temporal_typecast
   bool get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date);
   const char *cast_type() const { return "time"; }
   enum_field_types field_type() const { return MYSQL_TYPE_TIME; }
+  const Type_handler *type_handler() const { return &type_handler_time2; }
   void fix_length_and_dec()
   {
     args[0]->type_handler()->Item_time_typecast_fix_length_and_dec(this);
@@ -1109,6 +1121,7 @@ class Item_datetime_typecast :public Item_temporal_typecast
   const char *func_name() const { return "cast_as_datetime"; }
   const char *cast_type() const { return "datetime"; }
   enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
+  const Type_handler *type_handler() const { return &type_handler_datetime2; }
   bool get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date);
   void fix_length_and_dec()
   {

sql/item_windowfunc.h

@@ -309,6 +309,8 @@ class Item_sum_hybrid_simple : public Item_sum,
   { return Type_handler_hybrid_field_type::cmp_type(); }
   enum enum_field_types field_type() const
   { return Type_handler_hybrid_field_type::field_type(); }
+  const Type_handler *type_handler() const
+  { return Type_handler_hybrid_field_type::type_handler(); }
   void update_field();
   Field *create_tmp_field(bool group, TABLE *table);
   void clear()
@@ -513,6 +515,7 @@ class Item_sum_percent_rank: public Item_sum_window_with_row_count
   bool add();
   enum Item_result result_type () const { return REAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
 
   void fix_length_and_dec()
   {
@@ -599,6 +602,7 @@ class Item_sum_cume_dist: public Item_sum_window_with_row_count
   void update_field() {}
   enum Item_result result_type () const { return REAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
 
   void fix_length_and_dec()
   {
@@ -676,6 +680,7 @@ class Item_sum_ntile : public Item_sum_window_with_row_count
 
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_sum_ntile>(thd, mem_root, this); }
@@ -804,6 +809,10 @@ class Item_window_func : public Item_func_or_sum
   { 
     return ((Item_sum *) args[0])->field_type(); 
   }
+  const Type_handler *type_handler() const
+  {
+    return ((Item_sum *) args[0])->type_handler();
+  }
   enum Item::Type type() const { return Item::WINDOW_FUNC_ITEM; }
 
 private:

sql/procedure.h

@@ -48,6 +48,7 @@ class Item_proc :public Item
   virtual void set(const char *str,uint length,CHARSET_INFO *cs)=0;
   virtual void set(longlong nr)=0;
   virtual enum_field_types field_type() const=0;
+  const Type_handler *type_handler() const=0;
   void set(const char *str) { set(str,(uint) strlen(str), default_charset()); }
   void make_field(THD *thd, Send_field *tmp_field)
   {
@@ -74,6 +75,7 @@ class Item_proc_real :public Item_proc
   enum Item_result result_type () const { return REAL_RESULT; }
   enum Item_result cmp_type () const { return REAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
+  const Type_handler *type_handler() const { return &type_handler_double; }
   void set(double nr) { value=nr; }
   void set(longlong nr) { value=(double) nr; }
   void set(const char *str,uint length,CHARSET_INFO *cs)
@@ -102,6 +104,7 @@ class Item_proc_int :public Item_proc
   enum Item_result result_type () const { return INT_RESULT; }
   enum Item_result cmp_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
+  const Type_handler *type_handler() const { return &type_handler_longlong; }
   void set(double nr) { value=(longlong) nr; }
   void set(longlong nr) { value=nr; }
   void set(const char *str,uint length, CHARSET_INFO *cs)
@@ -122,6 +125,7 @@ class Item_proc_string :public Item_proc
   enum Item_result result_type () const { return STRING_RESULT; }
   enum Item_result cmp_type () const { return STRING_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; }
+  const Type_handler *type_handler() const { return &type_handler_varchar; }
   void set(double nr) { str_value.set_real(nr, 2, default_charset()); }
   void set(longlong nr) { str_value.set(nr, default_charset()); }
   void set(const char *str, uint length, CHARSET_INFO *cs)