Merge with 5.1-microseconds

A lot of small fixes and new test cases.

client/mysqlbinlog.cc:
  Cast removed
client/mysqltest.cc:
  Added missing DBUG_RETURN
include/my_pthread.h:
  set_timespec_time_nsec() now only takes one argument
mysql-test/t/date_formats.test:
  Remove --disable_ps_protocl as now also ps supports microseconds
mysys/my_uuid.c:
  Changed to use my_interval_timer() instead of my_getsystime()
mysys/waiting_threads.c:
  Changed to use my_hrtime()
sql/field.h:
  Added bool special_const_compare() for fields that may convert values before compare (like year)
sql/field_conv.cc:
  Added test to get optimal copying of identical temporal values.
sql/item.cc:
  Return that item_int is equal if it's positive, even if unsigned flag is different.
  Fixed Item_cache_str::save_in_field() to have identical null check as other similar functions
  Added proper NULL check to Item_cache_int::save_in_field()
sql/item_cmpfunc.cc:
  Don't call convert_constant_item() if there is nothing that is worth converting.
  Simplified test when years should be converted
sql/item_sum.cc:
  Mark cache values in Item_sum_hybrid as not constants to ensure they are not replaced by other cache values in compare_datetime()
sql/item_timefunc.cc:
  Changed sec_to_time() to take a my_decimal argument to ensure we don't loose any sub seconds.
  Added Item_temporal_func::get_time() (This simplifies some things)
sql/mysql_priv.h:
  Added Lazy_string_decimal()
sql/mysqld.cc:
  Added my_decimal constants max_seconds_for_time_type, time_second_part_factor
sql/table.cc:
  Changed expr_arena to be of type CONVENTIONAL_EXECUTION to ensure that we don't loose any items that are created by fix_fields()
sql/tztime.cc:
  TIME_to_gmt_sec() now sets *in_dst_time_gap in case of errors
  This is needed to be able to detect if timestamp is 0
storage/maria/lockman.c:
  Changed from my_getsystime() to set_timespec_time_nsec()
storage/maria/ma_loghandler.c:
  Changed from my_getsystime() to my_hrtime()
storage/maria/ma_recovery.c:
  Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/maria/unittest/trnman-t.c:
  Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/xtradb/handler/ha_innodb.cc:
  Added support for new time,datetime and timestamp
unittest/mysys/thr_template.c:
  my_getsystime() -> my_interval_timer()
unittest/mysys/waiting_threads-t.c:
  my_getsystime() -> my_interval_timer()

1 files changed, 177 insertions, 341 deletions

diff --git a/sql/item_timefunc.h b/sql/item_timefunc.h
index 27c3401a6a9..d9559794c00 100644
--- a/sql/item_timefunc.h
+++ b/sql/item_timefunc.h
@@ -358,15 +358,38 @@ class Item_func_dayname :public Item_func_weekday
 };
 
 
-class Item_func_unix_timestamp :public Item_int_func
+class Item_func_seconds_hybrid: public Item_func_numhybrid
 {
-  String value;
 public:
-  Item_func_unix_timestamp() :Item_int_func() {}
-  Item_func_unix_timestamp(Item *a) :Item_int_func(a) {}
-  longlong val_int();
+  Item_func_seconds_hybrid() :Item_func_numhybrid() {}
+  Item_func_seconds_hybrid(Item *a) :Item_func_numhybrid(a) {}
+  void fix_num_length_and_dec()
+  {
+    if (arg_count)
+      decimals= args[0]->decimals;
+    if (decimals != NOT_FIXED_DEC)
+      set_if_smaller(decimals, TIME_SECOND_PART_DIGITS);
+    max_length=17 + (decimals ? decimals + 1 : 0);
+  }
+  void find_num_type() { hybrid_type= decimals ? REAL_RESULT : INT_RESULT; }
+  my_decimal *decimal_op(my_decimal* buf) { DBUG_ASSERT(0); return 0; }
+  String *str_op(String *str) { DBUG_ASSERT(0); return 0; }
+};
+
+
+class Item_func_unix_timestamp :public Item_func_seconds_hybrid
+{
+  bool get_timestamp_value(my_time_t *seconds, ulong *second_part);
+public:
+  Item_func_unix_timestamp() :Item_func_seconds_hybrid() {}
+  Item_func_unix_timestamp(Item *a) :Item_func_seconds_hybrid(a) {}
   const char *func_name() const { return "unix_timestamp"; }
   bool check_partition_func_processor(uchar *int_arg) {return FALSE;}
+  void fix_num_length_and_dec()
+  {
+    maybe_null= false;
+    Item_func_seconds_hybrid::fix_num_length_and_dec();
+  }
   /*
     UNIX_TIMESTAMP() depends on the current timezone
     (and thus may not be used as a partitioning function)
@@ -376,11 +399,6 @@ public:
   {
     return !has_timestamp_args();
   }
-  void fix_length_and_dec()
-  {
-    decimals=0;
-    max_length=10*MY_CHARSET_BIN_MB_MAXLEN;
-  }
   bool check_vcol_func_processor(uchar *int_arg) 
   {
     /*
@@ -389,20 +407,21 @@ public:
     */
     return trace_unsupported_by_check_vcol_func_processor(func_name());
   }
+  longlong int_op();
+  double real_op();
 };
 
 
-class Item_func_time_to_sec :public Item_int_func
+  
+class Item_func_time_to_sec :public Item_func_seconds_hybrid
 {
 public:
-  Item_func_time_to_sec(Item *item) :Item_int_func(item) {}
-  longlong val_int();
+  Item_func_time_to_sec(Item *item) :Item_func_seconds_hybrid(item) {}
   const char *func_name() const { return "time_to_sec"; }
-  void fix_length_and_dec()
+  void fix_num_length_and_dec()
   {
-    maybe_null= TRUE;
-    decimals=0;
-    max_length=10*MY_CHARSET_BIN_MB_MAXLEN;
+    maybe_null= true;
+    Item_func_seconds_hybrid::fix_num_length_and_dec();
   }
   bool check_partition_func_processor(uchar *int_arg) {return FALSE;}
   bool check_vcol_func_processor(uchar *int_arg) { return FALSE;}
@@ -410,126 +429,101 @@ public:
   {
     return !has_time_args();
   }
+  longlong int_op();
+  double real_op();
 };
 
 
-/*
-  This can't be a Item_str_func, because the val_real() functions are special
-*/
-
-class Item_date :public Item_func
+class Item_temporal_func: public Item_func
 {
 public:
-  Item_date() :Item_func() {}
-  Item_date(Item *a) :Item_func(a) {}
+  Item_temporal_func() :Item_func() {}
+  Item_temporal_func(Item *a) :Item_func(a) {}
+  Item_temporal_func(Item *a, Item *b) :Item_func(a,b) {}
+  Item_temporal_func(Item *a, Item *b, Item *c) :Item_func(a,b,c) {}
   enum Item_result result_type () const { return STRING_RESULT; }
-  enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
+  enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
   String *val_str(String *str);
   longlong val_int();
-  double val_real() { return val_real_from_decimal(); }
-  const char *func_name() const { return "date"; }
-  void fix_length_and_dec()
-  { 
-    collation.set(&my_charset_bin);
-    decimals=0;
-    max_length=MAX_DATE_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
-  }
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 0);
-  }
-  bool result_as_longlong() { return TRUE; }
+  double val_real();
+  bool get_date(MYSQL_TIME *res, uint fuzzy_date) { DBUG_ASSERT(0); return 1; }
+  bool get_time(MYSQL_TIME *res);
   my_decimal *val_decimal(my_decimal *decimal_value)
-  {
-    DBUG_ASSERT(fixed == 1);
-    return  val_decimal_from_date(decimal_value);
-  }
+  { return  val_decimal_from_date(decimal_value); }
+  Field *tmp_table_field(TABLE *table)
+  { return tmp_table_field_from_field_type(table, 0); }
   int save_in_field(Field *field, bool no_conversions)
-  {
-    return save_date_in_field(field);
+  { return save_date_in_field(field); }
+  void fix_length_and_dec()
+  { 
+    static const uint max_time_type_width[5]=
+    { MAX_DATETIME_WIDTH, MAX_DATETIME_WIDTH, MAX_DATE_WIDTH,
+      MAX_DATETIME_WIDTH, MIN_TIME_WIDTH };
+
+    max_length= max_time_type_width[mysql_type_to_time_type(field_type())+2];
+    if (decimals)
+    {
+      if (decimals == NOT_FIXED_DEC)
+        max_length+= TIME_SECOND_PART_DIGITS + 1;
+      else
+      {
+        set_if_smaller(decimals, TIME_SECOND_PART_DIGITS);
+        max_length+= decimals + 1;
+      }
+    }
+    /*
+      We set maybe_null to 1 as default as any bad argument with date or
+      time can get us to return NULL.
+    */ 
+    maybe_null= 1;
   }
 };
 
 
-class Item_date_func :public Item_str_func
+class Item_datefunc :public Item_temporal_func
 {
 public:
-  Item_date_func() :Item_str_func() {}
-  Item_date_func(Item *a) :Item_str_func(a) {}
-  Item_date_func(Item *a,Item *b) :Item_str_func(a,b) {}
-  Item_date_func(Item *a,Item *b, Item *c) :Item_str_func(a,b,c) {}
-  enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 0);
-  }
-  bool result_as_longlong() { return TRUE; }
-  double val_real() { return (double) val_int(); }
-  my_decimal *val_decimal(my_decimal *decimal_value)
-  {
-    DBUG_ASSERT(fixed == 1);
-    return  val_decimal_from_date(decimal_value);
-  }
-  int save_in_field(Field *field, bool no_conversions)
-  {
-    return save_date_in_field(field);
-  }
+  Item_datefunc() :Item_temporal_func() { }
+  Item_datefunc(Item *a) :Item_temporal_func(a) { }
+  enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
+  const char *func_name() const { return "date"; }
+  bool get_date(MYSQL_TIME *res, uint fuzzy_date)
+  { return get_arg0_date(res, fuzzy_date); }
 };
 
 
-class Item_str_timefunc :public Item_str_func
+class Item_timefunc :public Item_temporal_func
 {
 public:
-  Item_str_timefunc() :Item_str_func() {}
-  Item_str_timefunc(Item *a) :Item_str_func(a) {}
-  Item_str_timefunc(Item *a,Item *b) :Item_str_func(a,b) {}
-  Item_str_timefunc(Item *a, Item *b, Item *c) :Item_str_func(a, b ,c) {}
+  Item_timefunc() :Item_temporal_func() {}
+  Item_timefunc(Item *a) :Item_temporal_func(a) {}
+  Item_timefunc(Item *a,Item *b) :Item_temporal_func(a,b) {}
+  Item_timefunc(Item *a, Item *b, Item *c) :Item_temporal_func(a, b ,c) {}
   enum_field_types field_type() const { return MYSQL_TYPE_TIME; }
-  void fix_length_and_dec()
-  {
-    decimals= DATETIME_DEC;
-    max_length=MAX_TIME_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
-  }
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 0);
-  }
-  double val_real() { return val_real_from_decimal(); }
-  my_decimal *val_decimal(my_decimal *decimal_value)
-  {
-    DBUG_ASSERT(fixed == 1);
-    return  val_decimal_from_time(decimal_value);
-  }
-  int save_in_field(Field *field, bool no_conversions)
-  {
-    return save_time_in_field(field);
-  }
-  longlong val_int() { return val_int_from_decimal(); }
-  bool result_as_longlong() { return TRUE; }
 };
 
 
 /* Abstract CURTIME function. Children should define what time zone is used */
 
-class Item_func_curtime :public Item_str_timefunc
+class Item_func_curtime :public Item_timefunc
 {
-  longlong value;
-  char buff[9*2+32];
-  uint buff_length;
+  MYSQL_TIME ltime;
 public:
-  Item_func_curtime() :Item_str_timefunc() {}
-  Item_func_curtime(Item *a) :Item_str_timefunc(a) {}
-  double val_real() { DBUG_ASSERT(fixed == 1); return (double) value; }
-  longlong val_int() { DBUG_ASSERT(fixed == 1); return value; }
-  String *val_str(String *str);
-  void fix_length_and_dec();
+  Item_func_curtime(uint dec) :Item_timefunc() { decimals= dec; }
+  bool fix_fields(THD *, Item **);
+  void fix_length_and_dec()
+  {
+    store_now_in_TIME(&ltime);
+    Item_timefunc::fix_length_and_dec();
+    maybe_null= 0;
+  }
+  bool get_date(MYSQL_TIME *res, uint fuzzy_date);
   /* 
     Abstract method that defines which time zone is used for conversion.
     Converts time current time in my_time_t representation to broken-down
     MYSQL_TIME representation using UTC-SYSTEM or per-thread time zone.
   */
   virtual void store_now_in_TIME(MYSQL_TIME *now_time)=0;
-  bool result_as_longlong() { return TRUE; }
   bool check_vcol_func_processor(uchar *int_arg) 
   {
     return trace_unsupported_by_check_vcol_func_processor(func_name());
@@ -540,8 +534,7 @@ public:
 class Item_func_curtime_local :public Item_func_curtime
 {
 public:
-  Item_func_curtime_local() :Item_func_curtime() {}
-  Item_func_curtime_local(Item *a) :Item_func_curtime(a) {}
+  Item_func_curtime_local(uint dec) :Item_func_curtime(dec) {}
   const char *func_name() const { return "curtime"; }
   virtual void store_now_in_TIME(MYSQL_TIME *now_time);
 };
@@ -550,8 +543,7 @@ public:
 class Item_func_curtime_utc :public Item_func_curtime
 {
 public:
-  Item_func_curtime_utc() :Item_func_curtime() {}
-  Item_func_curtime_utc(Item *a) :Item_func_curtime(a) {}
+  Item_func_curtime_utc(uint dec) :Item_func_curtime(dec) {}
   const char *func_name() const { return "utc_time"; }
   virtual void store_now_in_TIME(MYSQL_TIME *now_time);
 };
@@ -559,14 +551,11 @@ public:
 
 /* Abstract CURDATE function. See also Item_func_curtime. */
 
-class Item_func_curdate :public Item_date
+class Item_func_curdate :public Item_datefunc
 {
-  longlong value;
   MYSQL_TIME ltime;
 public:
-  Item_func_curdate() :Item_date() {}
-  longlong val_int() { DBUG_ASSERT(fixed == 1); return (value) ; }
-  String *val_str(String *str);
+  Item_func_curdate() :Item_datefunc() {}
   void fix_length_and_dec();
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
   virtual void store_now_in_TIME(MYSQL_TIME *now_time)=0;
@@ -597,21 +586,19 @@ public:
 
 /* Abstract CURRENT_TIMESTAMP function. See also Item_func_curtime */
 
-class Item_func_now :public Item_date_func
+
+class Item_func_now :public Item_temporal_func
 {
-protected:
-  longlong value;
-  char buff[20*2+32];	// +32 to make my_snprintf_{8bit|ucs2} happy
-  uint buff_length;
   MYSQL_TIME ltime;
 public:
-  Item_func_now() :Item_date_func() {}
-  Item_func_now(Item *a) :Item_date_func(a) {}
-  enum Item_result result_type () const { return STRING_RESULT; }
-  longlong val_int() { DBUG_ASSERT(fixed == 1); return value; }
-  int save_in_field(Field *to, bool no_conversions);
-  String *val_str(String *str);
-  void fix_length_and_dec();
+  Item_func_now(uint dec) :Item_temporal_func() { decimals= dec; }
+  bool fix_fields(THD *, Item **);
+  void fix_length_and_dec()
+  {
+    store_now_in_TIME(&ltime);
+    Item_temporal_func::fix_length_and_dec();
+    maybe_null= 0;
+  }
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
   virtual void store_now_in_TIME(MYSQL_TIME *now_time)=0;
   bool check_vcol_func_processor(uchar *int_arg) 
@@ -624,8 +611,7 @@ public:
 class Item_func_now_local :public Item_func_now
 {
 public:
-  Item_func_now_local() :Item_func_now() {}
-  Item_func_now_local(Item *a) :Item_func_now(a) {}
+  Item_func_now_local(uint dec) :Item_func_now(dec) {}
   const char *func_name() const { return "now"; }
   virtual void store_now_in_TIME(MYSQL_TIME *now_time);
   virtual enum Functype functype() const { return NOW_FUNC; }
@@ -635,8 +621,7 @@ public:
 class Item_func_now_utc :public Item_func_now
 {
 public:
-  Item_func_now_utc() :Item_func_now() {}
-  Item_func_now_utc(Item *a) :Item_func_now(a) {}
+  Item_func_now_utc(uint dec) :Item_func_now(dec) {}
   const char *func_name() const { return "utc_timestamp"; }
   virtual void store_now_in_TIME(MYSQL_TIME *now_time);
 };
@@ -649,16 +634,10 @@ public:
 class Item_func_sysdate_local :public Item_func_now
 {
 public:
-  Item_func_sysdate_local() :Item_func_now() {}
-  Item_func_sysdate_local(Item *a) :Item_func_now(a) {}
+  Item_func_sysdate_local(uint dec) :Item_func_now(dec) {}
   bool const_item() const { return 0; }
   const char *func_name() const { return "sysdate"; }
   void store_now_in_TIME(MYSQL_TIME *now_time);
-  double val_real();
-  longlong val_int();
-  int save_in_field(Field *to, bool no_conversions);
-  String *val_str(String *str);
-  void fix_length_and_dec();
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
   void update_used_tables()
   {
@@ -668,10 +647,10 @@ public:
 };
 
 
-class Item_func_from_days :public Item_date
+class Item_func_from_days :public Item_datefunc
 {
 public:
-  Item_func_from_days(Item *a) :Item_date(a) {}
+  Item_func_from_days(Item *a) :Item_datefunc(a) {}
   const char *func_name() const { return "from_days"; }
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
   bool check_partition_func_processor(uchar *int_arg) {return FALSE;}
@@ -700,13 +679,11 @@ public:
 };
 
 
-class Item_func_from_unixtime :public Item_date_func
+class Item_func_from_unixtime :public Item_temporal_func
 {
   THD *thd;
  public:
-  Item_func_from_unixtime(Item *a) :Item_date_func(a) {}
-  longlong val_int();
-  String *val_str(String *str);
+  Item_func_from_unixtime(Item *a) :Item_temporal_func(a) {}
   const char *func_name() const { return "from_unixtime"; }
   void fix_length_and_dec();
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
@@ -727,7 +704,7 @@ class Time_zone;
   tables can be used during this function calculation for loading time zone
   descriptions.
 */
-class Item_func_convert_tz :public Item_date_func
+class Item_func_convert_tz :public Item_temporal_func
 {
   /*
     If time zone parameters are constants we are caching objects that
@@ -739,9 +716,7 @@ class Item_func_convert_tz :public Item_date_func
   Time_zone *from_tz, *to_tz;
  public:
   Item_func_convert_tz(Item *a, Item *b, Item *c):
-    Item_date_func(a, b, c), from_tz_cached(0), to_tz_cached(0) {}
-  longlong val_int();
-  String *val_str(String *str);
+    Item_temporal_func(a, b, c), from_tz_cached(0), to_tz_cached(0) {}
   const char *func_name() const { return "convert_tz"; }
   void fix_length_and_dec();
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
@@ -749,29 +724,22 @@ class Item_func_convert_tz :public Item_date_func
 };
 
 
-class Item_func_sec_to_time :public Item_str_timefunc
+class Item_func_sec_to_time :public Item_timefunc
 {
+  bool sec_to_time(my_decimal *seconds, MYSQL_TIME *ltime);
 public:
-  Item_func_sec_to_time(Item *item) :Item_str_timefunc(item) {}
-  double val_real()
-  {
-    DBUG_ASSERT(fixed == 1);
-    return (double) Item_func_sec_to_time::val_int();
-  }
-  longlong val_int();
-  String *val_str(String *);
+  Item_func_sec_to_time(Item *item) :Item_timefunc(item) {}
+  bool get_date(MYSQL_TIME *res, uint fuzzy_date);
   void fix_length_and_dec()
-  { 
-    Item_str_timefunc::fix_length_and_dec();
-    collation.set(&my_charset_bin);
-    maybe_null=1;
+  {
+    decimals= args[0]->decimals;
+    Item_timefunc::fix_length_and_dec();
   }
   const char *func_name() const { return "sec_to_time"; }
-  bool result_as_longlong() { return TRUE; }
 };
 
 
-class Item_date_add_interval :public Item_date_func
+class Item_date_add_interval :public Item_temporal_func
 {
   String value;
   enum_field_types cached_field_type;
@@ -780,12 +748,10 @@ public:
   const interval_type int_type; // keep it public
   const bool date_sub_interval; // keep it public
   Item_date_add_interval(Item *a,Item *b,interval_type type_arg,bool neg_arg)
-    :Item_date_func(a,b),int_type(type_arg), date_sub_interval(neg_arg) {}
-  String *val_str(String *);
+    :Item_temporal_func(a,b),int_type(type_arg), date_sub_interval(neg_arg) {}
   const char *func_name() const { return "date_add_interval"; }
   void fix_length_and_dec();
   enum_field_types field_type() const { return cached_field_type; }
-  longlong val_int();
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
   bool eq(const Item *item, bool binary_cmp) const;
   virtual void print(String *str, enum_query_type query_type);
@@ -846,184 +812,84 @@ class Item_extract :public Item_int_func
 };
 
 
-class Item_typecast :public Item_str_func
-{
-public:
-  Item_typecast(Item *a) :Item_str_func(a) {}
-  String *val_str(String *a)
-  {
-    DBUG_ASSERT(fixed == 1);
-    String *tmp=args[0]->val_str(a);
-    null_value=args[0]->null_value;
-    if (tmp)
-      tmp->set_charset(collation.collation);
-    return tmp;
-  }
-  void fix_length_and_dec()
-  {
-    collation.set(&my_charset_bin);
-    max_length=args[0]->max_length;
-  }
-  virtual const char* cast_type() const= 0;
-  virtual void print(String *str, enum_query_type query_type);
-};
-
-
-class Item_typecast_maybe_null :public Item_typecast
-{
-public:
-  Item_typecast_maybe_null(Item *a) :Item_typecast(a) {}
-  void fix_length_and_dec()
-  {
-    collation.set(&my_charset_bin);
-    max_length=args[0]->max_length;
-    maybe_null= 1;
-  }
-};
-
-
-class Item_char_typecast :public Item_typecast
+class Item_char_typecast :public Item_str_func
 {
-  int cast_length;
+  uint cast_length;
   CHARSET_INFO *cast_cs, *from_cs;
   bool charset_conversion;
   String tmp_value;
 public:
-  Item_char_typecast(Item *a, int length_arg, CHARSET_INFO *cs_arg)
-    :Item_typecast(a), cast_length(length_arg), cast_cs(cs_arg) {}
+  Item_char_typecast(Item *a, uint length_arg, CHARSET_INFO *cs_arg)
+    :Item_str_func(a), cast_length(length_arg), cast_cs(cs_arg) {}
   enum Functype functype() const { return CHAR_TYPECAST_FUNC; }
   bool eq(const Item *item, bool binary_cmp) const;
   const char *func_name() const { return "cast_as_char"; }
-  const char* cast_type() const { return "char"; };
   String *val_str(String *a);
   void fix_length_and_dec();
-  virtual void print(String *str, enum_query_type query_type);
+  void print(String *str, enum_query_type query_type);
 };
 
 
-class Item_date_typecast :public Item_typecast_maybe_null
+class Item_temporal_typecast: public Item_temporal_func
+{
+public:
+  Item_temporal_typecast(Item *a) :Item_temporal_func(a) {}
+  virtual const char *cast_type() const = 0;
+  void print(String *str, enum_query_type query_type);
+  void fix_length_and_dec()
+  {
+    if (decimals == NOT_FIXED_DEC)
+      decimals= args[0]->decimals;
+    Item_temporal_func::fix_length_and_dec();
+  }
+};
+
+class Item_date_typecast :public Item_temporal_typecast
 {
 public:
-  Item_date_typecast(Item *a) :Item_typecast_maybe_null(a) {}
+  Item_date_typecast(Item *a) :Item_temporal_typecast(a) {}
   const char *func_name() const { return "cast_as_date"; }
-  String *val_str(String *str);
   bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
-  bool get_time(MYSQL_TIME *ltime);
   const char *cast_type() const { return "date"; }
   enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 0);
-  }  
-  void fix_length_and_dec()
-  {
-    collation.set(&my_charset_bin);
-    max_length= 10;
-    maybe_null= 1;
-  }
-  bool result_as_longlong() { return TRUE; }
-  longlong val_int();
-  double val_real() { return (double) val_int(); }
-  my_decimal *val_decimal(my_decimal *decimal_value)
-  {
-    DBUG_ASSERT(fixed == 1);
-    return  val_decimal_from_date(decimal_value);
-  }
-  int save_in_field(Field *field, bool no_conversions)
-  {
-    return save_date_in_field(field);
-  }
 };
 
 
-class Item_time_typecast :public Item_typecast_maybe_null
+class Item_time_typecast :public Item_temporal_typecast
 {
 public:
-  Item_time_typecast(Item *a) :Item_typecast_maybe_null(a) {}
+  Item_time_typecast(Item *a, uint dec_arg)
+    :Item_temporal_typecast(a) { decimals= dec_arg; }
   const char *func_name() const { return "cast_as_time"; }
   bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
-  String *val_str(String *str);
-  bool get_time(MYSQL_TIME *ltime);
   const char *cast_type() const { return "time"; }
   enum_field_types field_type() const { return MYSQL_TYPE_TIME; }
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 0);
-  }
-  void fix_length_and_dec()
-  {
-    collation.set(&my_charset_bin);
-    max_length= 17;
-    maybe_null= 1;
-  }
-  bool result_as_longlong() { return TRUE; }
-  longlong val_int();
-  double val_real() { return val_real_from_decimal(); }
-  my_decimal *val_decimal(my_decimal *decimal_value)
-  {
-    DBUG_ASSERT(fixed == 1);
-    return  val_decimal_from_time(decimal_value);
-  }
-  int save_in_field(Field *field, bool no_conversions)
-  {
-    return save_time_in_field(field);
-  }
 };
 
 
-class Item_datetime_typecast :public Item_typecast_maybe_null
+class Item_datetime_typecast :public Item_temporal_typecast
 {
 public:
-  Item_datetime_typecast(Item *a) :Item_typecast_maybe_null(a) {}
+  Item_datetime_typecast(Item *a, uint dec_arg)
+    :Item_temporal_typecast(a) { decimals= dec_arg; }
   const char *func_name() const { return "cast_as_datetime"; }
-  String *val_str(String *str);
   const char *cast_type() const { return "datetime"; }
   enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 0);
-  }
-  void fix_length_and_dec()
-  {
-    collation.set(&my_charset_bin);
-    maybe_null= 1;
-    max_length= MAX_DATETIME_FULL_WIDTH * MY_CHARSET_BIN_MB_MAXLEN;
-    decimals= DATETIME_DEC;
-  }
-  bool result_as_longlong() { return TRUE; }
-  longlong val_int();
-  double val_real() { return val_real_from_decimal(); }
-  double val() { return (double) val_int(); }
-  my_decimal *val_decimal(my_decimal *decimal_value)
-  {
-    DBUG_ASSERT(fixed == 1);
-    return  val_decimal_from_date(decimal_value);
-  }
-  int save_in_field(Field *field, bool no_conversions)
-  {
-    return save_date_in_field(field);
-  }
+  bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
 };
 
-class Item_func_makedate :public Item_date_func
+
+class Item_func_makedate :public Item_temporal_func
 {
 public:
-  Item_func_makedate(Item *a,Item *b) :Item_date_func(a,b) {}
-  String *val_str(String *str);
+  Item_func_makedate(Item *a,Item *b) :Item_temporal_func(a,b) {}
   const char *func_name() const { return "makedate"; }
   enum_field_types field_type() const { return MYSQL_TYPE_DATE; }
-  void fix_length_and_dec()
-  { 
-    decimals=0;
-    max_length=MAX_DATE_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
-    /* It returns NULL when the second argument is less or equal to 0 */
-    maybe_null= 1;
-  }
-  longlong val_int();
+  bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
 };
 
 
-class Item_func_add_time :public Item_str_func
+class Item_func_add_time :public Item_temporal_func
 {
   const bool is_date;
   int sign;
@@ -1031,63 +897,39 @@ class Item_func_add_time :public Item_str_func
 
 public:
   Item_func_add_time(Item *a, Item *b, bool type_arg, bool neg_arg)
-    :Item_str_func(a, b), is_date(type_arg) { sign= neg_arg ? -1 : 1; }
-  String *val_str(String *str);
+    :Item_temporal_func(a, b), is_date(type_arg) { sign= neg_arg ? -1 : 1; }
   enum_field_types field_type() const { return cached_field_type; }
   void fix_length_and_dec();
-
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 0);
-  }
+  bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
   virtual void print(String *str, enum_query_type query_type);
   const char *func_name() const { return "add_time"; }
-  double val_real() { return val_real_from_decimal(); }
-  my_decimal *val_decimal(my_decimal *decimal_value)
-  {
-    DBUG_ASSERT(fixed == 1);
-    if (cached_field_type == MYSQL_TYPE_TIME)
-      return  val_decimal_from_time(decimal_value);
-    if (cached_field_type == MYSQL_TYPE_DATETIME)
-      return  val_decimal_from_date(decimal_value);
-    return Item_str_func::val_decimal(decimal_value);
-  }
-  int save_in_field(Field *field, bool no_conversions)
-  {
-    if (cached_field_type == MYSQL_TYPE_TIME)
-      return save_time_in_field(field);
-    if (cached_field_type == MYSQL_TYPE_DATETIME)
-      return save_date_in_field(field);
-    return Item_str_func::save_in_field(field, no_conversions);
-  }
 };
 
-class Item_func_timediff :public Item_str_timefunc
+class Item_func_timediff :public Item_timefunc
 {
 public:
   Item_func_timediff(Item *a, Item *b)
-    :Item_str_timefunc(a, b) {}
-  String *val_str(String *str);
+    :Item_timefunc(a, b) {}
   const char *func_name() const { return "timediff"; }
   void fix_length_and_dec()
   {
-    Item_str_timefunc::fix_length_and_dec();
-    maybe_null= 1;
+    decimals= max(args[0]->decimals, args[1]->decimals);
+    Item_timefunc::fix_length_and_dec();
   }
+  bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
 };
 
-class Item_func_maketime :public Item_str_timefunc
+class Item_func_maketime :public Item_timefunc
 {
 public:
   Item_func_maketime(Item *a, Item *b, Item *c)
-    :Item_str_timefunc(a, b, c) 
-  {
-    maybe_null= TRUE;
-  }
-  String *val_str(String *str);
+    :Item_timefunc(a, b, c) 
+  {}
   const char *func_name() const { return "maketime"; }
+  bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
 };
 
+
 class Item_func_microsecond :public Item_int_func
 {
 public:
@@ -1149,32 +991,26 @@ public:
 };
 
 
-class Item_func_str_to_date :public Item_str_func
+class Item_func_str_to_date :public Item_temporal_func
 {
   enum_field_types cached_field_type;
-  date_time_format_types cached_format_type;
   timestamp_type cached_timestamp_type;
   bool const_item;
 public:
   Item_func_str_to_date(Item *a, Item *b)
-    :Item_str_func(a, b), const_item(false)
+    :Item_temporal_func(a, b), const_item(false)
   {}
-  String *val_str(String *str);
   bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
   const char *func_name() const { return "str_to_date"; }
   enum_field_types field_type() const { return cached_field_type; }
   void fix_length_and_dec();
-  Field *tmp_table_field(TABLE *table)
-  {
-    return tmp_table_field_from_field_type(table, 1);
-  }
 };
 
 
-class Item_func_last_day :public Item_date
+class Item_func_last_day :public Item_datefunc
 {
 public:
-  Item_func_last_day(Item *a) :Item_date(a) {}
+  Item_func_last_day(Item *a) :Item_datefunc(a) {}
   const char *func_name() const { return "last_day"; }
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
 };