Make SYSDATE() behave as in Oracle: always the current datetime, not the

datetime of when the current statement began. This also makes SYSDATE()
not safe in replication. (Bug #12562)


mysql-test/r/func_time.result:
  Add new results
mysql-test/t/func_time.test:
  Add tests for new SYSDATE() behavior
sql/item_timefunc.cc:
  Add Item_func_sysdate_local implementation
sql/item_timefunc.h:
  Add Item_func_sysdate_local, so SYSDATE() can behave differently
  than NOW().
sql/lex.h:
  SYSDATE() is no longer an alias for NOW().
sql/sql_yacc.yy:
  Handle SYSDATE()

mysql-test/r/func_time.result

@@ -720,3 +720,43 @@ Warning	1292	Truncated incorrect datetime value: '2005-01-00'
 select time_format('100:00:00', '%H %k %h %I %l');
 time_format('100:00:00', '%H %k %h %I %l')
 100 100 04 04 4
+create table t1 (a timestamp default '2005-05-05 01:01:01',
+b timestamp default '2005-05-05 01:01:01');
+create function t_slow_sysdate() returns timestamp
+begin
+do sleep(2);
+return sysdate();
+end;
+//
+insert into t1 set a = sysdate(), b = t_slow_sysdate();//
+create trigger t_before before insert on t1
+for each row begin
+set new.b = t_slow_sysdate();
+end
+//
+insert into t1 set a = sysdate();
+select a != b from t1;
+a != b
+1
+1
+drop trigger t_before;
+drop function t_slow_sysdate;
+drop table t1;
+create table t1 (a datetime, i int, b datetime);
+insert into t1 select sysdate(), sleep(1), sysdate() from dual;
+select a != b from t1;
+a != b
+1
+drop table t1;
+create procedure t_sysdate()
+begin
+select sysdate() into @a;
+do sleep(2);
+select sysdate() into @b;
+select @a != @b;
+end;
+//
+call t_sysdate();
+@a != @b
+1
+drop procedure t_sysdate;

mysql-test/t/func_time.test

@@ -353,3 +353,55 @@ select last_day('2005-01-00');
 # the 0-11 range
 #
 select time_format('100:00:00', '%H %k %h %I %l');
+
+#
+# Bug #12562: Make SYSDATE behave like it does in Oracle: always the current
+#             time, regardless of magic to make NOW() always the same for the
+#             entirety of a statement.
+create table t1 (a timestamp default '2005-05-05 01:01:01',
+                 b timestamp default '2005-05-05 01:01:01');
+delimiter //;
+create function t_slow_sysdate() returns timestamp
+begin
+  do sleep(2);
+  return sysdate();
+end;
+//
+
+insert into t1 set a = sysdate(), b = t_slow_sysdate();//
+
+create trigger t_before before insert on t1
+for each row begin
+  set new.b = t_slow_sysdate();
+end
+//
+
+delimiter ;//
+
+insert into t1 set a = sysdate();
+
+select a != b from t1;
+
+drop trigger t_before;
+drop function t_slow_sysdate;
+drop table t1;
+
+create table t1 (a datetime, i int, b datetime);
+insert into t1 select sysdate(), sleep(1), sysdate() from dual;
+select a != b from t1;
+drop table t1;
+
+delimiter //;
+create procedure t_sysdate()
+begin
+  select sysdate() into @a;
+  do sleep(2);
+  select sysdate() into @b;
+  select @a != @b;
+end;
+//
+delimiter ;//
+call t_sysdate();
+drop procedure t_sysdate;
+
+# End of 5.0 tests

sql/item_timefunc.cc

@@ -1478,7 +1478,7 @@ void Item_func_now_utc::store_now_in_TIME(TIME *now_time)
 bool Item_func_now::get_date(TIME *res,
                              uint fuzzy_date __attribute__((unused)))
 {
-  *res=ltime;
+  *res= ltime;
   return 0;
 }
 
@@ -1491,6 +1491,70 @@ int Item_func_now::save_in_field(Field *to, bool no_conversions)
 }
 
 
+/*
+    Converts current time in my_time_t to TIME represenatation for local
+    time zone. Defines time zone (local) used for whole SYSDATE function.
+*/
+void Item_func_sysdate_local::store_now_in_TIME(TIME *now_time)
+{
+  THD *thd= current_thd;
+  thd->variables.time_zone->gmt_sec_to_TIME(now_time, time(NULL));
+  thd->time_zone_used= 1;
+}
+
+
+String *Item_func_sysdate_local::val_str(String *str)
+{
+  DBUG_ASSERT(fixed == 1);
+  store_now_in_TIME(&ltime);
+  buff_length= (uint) my_datetime_to_str(&ltime, buff);
+  str_value.set(buff, buff_length, &my_charset_bin);
+  return &str_value;
+}
+
+
+longlong Item_func_sysdate_local::val_int()
+{
+  DBUG_ASSERT(fixed == 1);
+  store_now_in_TIME(&ltime);
+  return (longlong) TIME_to_ulonglong_datetime(&ltime);
+}
+
+
+double Item_func_sysdate_local::val_real()
+{
+  DBUG_ASSERT(fixed == 1);
+  store_now_in_TIME(&ltime);
+  return (longlong) TIME_to_ulonglong_datetime(&ltime);
+}
+
+
+void Item_func_sysdate_local::fix_length_and_dec()
+{
+  decimals= 0;
+  collation.set(&my_charset_bin);
+  max_length= MAX_DATETIME_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
+}
+
+
+bool Item_func_sysdate_local::get_date(TIME *res,
+                                       uint fuzzy_date __attribute__((unused)))
+{
+  store_now_in_TIME(&ltime);
+  *res= ltime;
+  return 0;
+}
+
+
+int Item_func_sysdate_local::save_in_field(Field *to, bool no_conversions)
+{
+  store_now_in_TIME(&ltime);
+  to->set_notnull();
+  to->store_time(&ltime, MYSQL_TIMESTAMP_DATETIME);
+  return 0;
+}
+
+
 String *Item_func_sec_to_time::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);

sql/item_timefunc.h

@@ -446,6 +446,7 @@ public:
 
 class Item_func_now :public Item_date_func
 {
+protected:
   longlong value;
   char buff[20*2+32];	// +32 to make my_snprintf_{8bit|ucs2} happy
   uint buff_length;
@@ -485,6 +486,32 @@ public:
 };
 
 
+/*
+  This is like NOW(), but always uses the real current time, not the
+  query_start(). This matches the Oracle behavior.
+*/
+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) {}
+  bool const_item() const { return 0; }
+  const char *func_name() const { return "sysdate"; }
+  void store_now_in_TIME(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(TIME *res, uint fuzzy_date);
+  void update_used_tables()
+  {
+    Item_func_now::update_used_tables();
+    used_tables_cache|= RAND_TABLE_BIT;
+  }
+};
+
+
 class Item_func_from_days :public Item_date
 {
 public:

sql/lex.h

@@ -751,7 +751,7 @@ static SYMBOL sql_functions[] = {
   { "SUBSTRING_INDEX",	SYM(SUBSTRING_INDEX)},
   { "SUBTIME",          F_SYM(FUNC_ARG2),0,CREATE_FUNC(create_func_subtime)},
   { "SUM",		SYM(SUM_SYM)},
-  { "SYSDATE",		SYM(NOW_SYM)},
+  { "SYSDATE",		SYM(SYSDATE)},
   { "SYSTEM_USER",	SYM(USER)},
   { "TAN",		F_SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_tan)},
   { "TIME_FORMAT",	F_SYM(FUNC_ARG2),0,CREATE_FUNC(create_func_time_format)},

sql/sql_yacc.yy

@@ -580,6 +580,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %token  SUM_SYM
 %token  SUPER_SYM
 %token  SUSPEND_SYM
+%token  SYSDATE
 %token  TABLES
 %token  TABLESPACE
 %token  TABLE_SYM
@@ -4683,6 +4684,10 @@ simple_expr:
 	  { $$= new Item_func_substr($3,$5); }
 	| SUBSTRING_INDEX '(' expr ',' expr ',' expr ')'
 	  { $$= new Item_func_substr_index($3,$5,$7); }
+	| SYSDATE optional_braces
+	  { $$= new Item_func_sysdate_local(); Lex->safe_to_cache_query=0;}
+	| SYSDATE '(' expr ')'
+	  { $$= new Item_func_sysdate_local($3); Lex->safe_to_cache_query=0;}
 	| TIME_SYM '(' expr ')'
 	  { $$= new Item_time_typecast($3); }
 	| TIMESTAMP '(' expr ')'