MDEV-4863 COALESCE(time_or_datetime) returns wrong results in numeric context

11 files changed, 628 insertions, 173 deletions

diff --git a/mysql-test/r/func_time.result b/mysql-test/r/func_time.result
index 88599b79a1f..8bbc692aa4a 100644
--- a/mysql-test/r/func_time.result
+++ b/mysql-test/r/func_time.result
@@ -1923,3 +1923,112 @@ NULL
 Warnings:
 Error	1411	Incorrect datetime value: '2020' for function str_to_date
 SET TIME_ZONE=DEFAULT;
+#
+#  MDEV-4863 COALESCE(time_or_datetime) returns wrong results in numeric context
+#
+CREATE TABLE t1 (a TIMESTAMP(3));
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30.999');
+SELECT CAST(COALESCE(a,a) AS SIGNED) AS c1, CAST(COALESCE(a,a) AS DECIMAL(25,3)) AS c2, ROUND(COALESCE(a,a)) AS c2  FROM t1;
+c1	c2	c2
+20010101102030	20010101102030.999	20010101102031
+DROP TABLE t1;
+CREATE TABLE t1 (a TIME(3));
+INSERT INTO t1 VALUES ('10:20:30.999');
+SELECT CAST(COALESCE(a,a) AS SIGNED) AS c1, CAST(COALESCE(a,a) AS DECIMAL(25,3)) AS c2, ROUND(COALESCE(a,a)) AS c2  FROM t1;
+c1	c2	c2
+102030	102030.999	102031
+DROP TABLE t1;
+SELECT
+CAST(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+CAST(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+CONCAT(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+TIME(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+DATE(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+TIMESTAMP(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010101000000	20010101000000.0000	20010101000000	2001-01-01 00:00:00.000000	00:00:00.000000	2001-01-01	2001-01-01 00:00:00.000000
+SELECT
+CAST(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS SIGNED) AS c1,
+CAST(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS DECIMAL(25,4)) AS c2,
+COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))+0e0 AS c3,
+CONCAT(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c4,
+TIME(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c5,
+DATE(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c6,
+TIMESTAMP(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010102102030	20010102102030.0000	20010102102030	2001-01-02 10:20:30.000000	10:20:30.000000	2001-01-02	2001-01-02 10:20:30.000000
+SELECT
+CAST(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+CAST(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+CONCAT(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+TIME(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+DATE(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+TIMESTAMP(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010101000000	20010101000000.0000	20010101000000	2001-01-01 00:00:00.000000	00:00:00.000000	2001-01-01	2001-01-01 00:00:00.000000
+SELECT
+CAST(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS SIGNED) AS c1,
+CAST(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS DECIMAL(25,4)) AS c2,
+IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))+0e0 AS c3,
+CONCAT(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c4,
+TIME(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c5,
+DATE(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c6,
+TIMESTAMP(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010102102030	20010102102030.0000	20010102102030	2001-01-02 10:20:30.000000	10:20:30.000000	2001-01-02	2001-01-02 10:20:30.000000
+SELECT
+CAST(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+CAST(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+CONCAT(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+TIME(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+DATE(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+TIMESTAMP(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010101000000	20010101000000.0000	20010101000000	2001-01-01 00:00:00.000000	00:00:00.000000	2001-01-01	2001-01-01 00:00:00.000000
+SELECT
+CAST(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+CAST(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+CONCAT(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+TIME(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+DATE(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+TIMESTAMP(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010102102030	20010102102030.0000	20010102102030	2001-01-02 10:20:30.000000	10:20:30.000000	2001-01-02	2001-01-02 10:20:30.000000
+SELECT
+CAST(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS SIGNED) AS c1,
+CAST(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS DECIMAL(25,4)) AS c2,
+CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END+0e0 AS c3,
+CONCAT(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c4,
+TIME(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c5,
+DATE(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c6,
+TIMESTAMP(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010101000000	20010101000000.0000	20010101000000	2001-01-01 00:00:00.000000	00:00:00.000000	2001-01-01	2001-01-01 00:00:00.000000
+SELECT
+CAST(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS SIGNED) AS c1,
+CAST(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS DECIMAL(25,4)) AS c2,
+CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END+0e0 AS c3,
+CONCAT(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c4,
+TIME(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c5,
+DATE(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c6,
+TIMESTAMP(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c7;
+c1	c2	c3	c4	c5	c6	c7
+20010102102030	20010102102030.0000	20010102102030	2001-01-02 10:20:30.000000	10:20:30.000000	2001-01-02	2001-01-02 10:20:30.000000
+CREATE TABLE t1 AS SELECT
+CONCAT(COALESCE(TIME(101010),TIME(101010))) AS c1,
+CONCAT(IF(0,TIME(101010),TIME(101010))) AS c2,
+CONCAT(IFNULL(TIME(101010),TIME(101010))) AS c3,
+CONCAT(CASE WHEN 1 THEN TIME(101010) ELSE TIME(101010) END) AS c4;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varbinary(10) DEFAULT NULL,
+  `c2` varbinary(10) DEFAULT NULL,
+  `c3` varbinary(10) DEFAULT NULL,
+  `c4` varbinary(10) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
diff --git a/mysql-test/r/type_datetime.result b/mysql-test/r/type_datetime.result
index 286a84c56e7..de0bc2a0b80 100644
--- a/mysql-test/r/type_datetime.result
+++ b/mysql-test/r/type_datetime.result
@@ -657,13 +657,8 @@ create table t1 (d date, t time) engine=myisam;
 insert into t1 values ('2000-12-03','22:55:23'),('2008-05-03','10:19:31');
 select case when d = '2012-12-12' then d else t end as cond, group_concat( d ) from t1 group by cond;
 cond	group_concat( d )
-NULL	2000-12-03
-NULL	2008-05-03
-Warnings:
-Warning	1292	Incorrect datetime value: '22:55:23'
-Warning	1292	Incorrect datetime value: '10:19:31'
-Warning	1292	Incorrect datetime value: '22:55:23'
-Warning	1292	Incorrect datetime value: '10:19:31'
+0000-00-00 10:19:31	2008-05-03
+0000-00-00 22:55:23	2000-12-03
 drop table t1;
 # 
 # Semantics of the condition <non-nullable datetime field> IS NULL 
diff --git a/mysql-test/t/func_time.test b/mysql-test/t/func_time.test
index ff2216802bf..6aedf3f55df 100644
--- a/mysql-test/t/func_time.test
+++ b/mysql-test/t/func_time.test
@@ -1162,3 +1162,96 @@ SELECT 1 FROM DUAL WHERE SECOND(TIMEDIFF(NULL, '12:12:12'));
 SET TIME_ZONE='+02:00';
 SELECT UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'));
 SET TIME_ZONE=DEFAULT;
+
+
+--echo #
+--echo #  MDEV-4863 COALESCE(time_or_datetime) returns wrong results in numeric context
+--echo #
+CREATE TABLE t1 (a TIMESTAMP(3));
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30.999');
+SELECT CAST(COALESCE(a,a) AS SIGNED) AS c1, CAST(COALESCE(a,a) AS DECIMAL(25,3)) AS c2, ROUND(COALESCE(a,a)) AS c2  FROM t1;
+DROP TABLE t1;
+CREATE TABLE t1 (a TIME(3));
+INSERT INTO t1 VALUES ('10:20:30.999');
+SELECT CAST(COALESCE(a,a) AS SIGNED) AS c1, CAST(COALESCE(a,a) AS DECIMAL(25,3)) AS c2, ROUND(COALESCE(a,a)) AS c2  FROM t1;
+DROP TABLE t1;
+
+SELECT
+  CAST(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+  CAST(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+  COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+  CONCAT(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+  TIME(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+  DATE(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+  TIMESTAMP(COALESCE(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+
+SELECT
+  CAST(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS SIGNED) AS c1,
+  CAST(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS DECIMAL(25,4)) AS c2,
+  COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))+0e0 AS c3,
+  CONCAT(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c4,
+  TIME(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c5,
+  DATE(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c6,
+  TIMESTAMP(COALESCE(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c7;
+
+SELECT
+  CAST(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+  CAST(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+  IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+  CONCAT(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+  TIME(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+  DATE(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+  TIMESTAMP(IFNULL(DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+
+SELECT
+  CAST(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS SIGNED) AS c1,
+  CAST(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01')) AS DECIMAL(25,4)) AS c2,
+  IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))+0e0 AS c3,
+  CONCAT(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c4,
+  TIME(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c5,
+  DATE(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c6,
+  TIMESTAMP(IFNULL(TIMESTAMP('2001-01-02 10:20:30'),DATE('2001-01-01'))) AS c7;
+
+SELECT
+  CAST(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+  CAST(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+  IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+  CONCAT(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+  TIME(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+  DATE(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+  TIMESTAMP(IF(1,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+
+SELECT
+  CAST(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS SIGNED) AS c1,
+  CAST(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30')) AS DECIMAL(25,4)) AS c2,
+  IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))+0e0 AS c3,
+  CONCAT(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c4,
+  TIME(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c5,
+  DATE(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c6,
+  TIMESTAMP(IF(0,DATE('2001-01-01'),TIMESTAMP('2001-01-02 10:20:30'))) AS c7;
+
+SELECT
+  CAST(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS SIGNED) AS c1,
+  CAST(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS DECIMAL(25,4)) AS c2,
+  CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END+0e0 AS c3,
+  CONCAT(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c4,
+  TIME(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c5,
+  DATE(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c6,
+  TIMESTAMP(CASE WHEN 1 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c7;
+
+SELECT
+  CAST(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS SIGNED) AS c1,
+  CAST(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END AS DECIMAL(25,4)) AS c2,
+  CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END+0e0 AS c3,
+  CONCAT(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c4,
+  TIME(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c5,
+  DATE(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c6,
+  TIMESTAMP(CASE WHEN 0 THEN DATE('2001-01-01') ELSE TIMESTAMP('2001-01-02 10:20:30') END) AS c7;
+
+CREATE TABLE t1 AS SELECT
+  CONCAT(COALESCE(TIME(101010),TIME(101010))) AS c1,
+  CONCAT(IF(0,TIME(101010),TIME(101010))) AS c2,
+  CONCAT(IFNULL(TIME(101010),TIME(101010))) AS c3,
+  CONCAT(CASE WHEN 1 THEN TIME(101010) ELSE TIME(101010) END) AS c4;
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
diff --git a/sql/field.h b/sql/field.h
index 665b784d820..c1ae476fede 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -52,6 +52,19 @@ inline uint get_set_pack_length(int elements)
   return len > 4 ? 8 : len;
 }
 
+/**
+  Tests if field type is temporal, i.e. represents
+  DATE, TIME, DATETIME or TIMESTAMP types in SQL.
+     
+  @param type    Field type, as returned by field->type().
+  @retval true   If field type is temporal
+  @retval false  If field type is not temporal
+*/
+inline bool is_temporal_type(enum_field_types type)
+{
+  return mysql_type_to_time_type(type) != MYSQL_TIMESTAMP_ERROR;
+}
+
 /*
   Virtual_column_info is the class to contain additional
   characteristics that is specific for a virtual/computed
diff --git a/sql/item.h b/sql/item.h
index c66573fc0ef..5613fe547c4 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -45,6 +45,14 @@ struct TABLE_LIST;
 void item_init(void);			/* Init item functions */
 class Item_field;
 
+static inline uint32
+char_to_byte_length_safe(uint32 char_length_arg, uint32 mbmaxlen_arg)
+{
+   ulonglong tmp= ((ulonglong) char_length_arg) * mbmaxlen_arg;
+   return (tmp > UINT_MAX32) ? (uint32) UINT_MAX32 : (uint32) tmp;
+}
+
+
 /*
    "Declared Type Collation"
    A combination of collation and its derivation.
@@ -1287,6 +1295,11 @@ public:
     { return Field::GEOM_GEOMETRY; };
   String *check_well_formed_result(String *str, bool send_error= 0);
   bool eq_by_collation(Item *item, bool binary_cmp, CHARSET_INFO *cs); 
+  void fix_char_length(uint32 max_char_length_arg)
+  {
+    max_length= char_to_byte_length_safe(max_char_length_arg,
+                                         collation.collation->mbmaxlen);
+  }
   Item* set_expr_cache(THD *thd);
   virtual Item *get_cached_item() { return NULL; }
 
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index e133e2811bd..f0069757ee3 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -2374,12 +2374,13 @@ void Item_func_between::print(String *str, enum_query_type query_type)
 void
 Item_func_ifnull::fix_length_and_dec()
 {
-  agg_result_type(&hybrid_type, args, 2);
+  agg_result_type(&cached_result_type, args, 2);
+  cached_field_type= agg_field_type(args, 2);
   maybe_null=args[1]->maybe_null;
   decimals= max(args[0]->decimals, args[1]->decimals);
   unsigned_flag= args[0]->unsigned_flag && args[1]->unsigned_flag;
 
-  if (hybrid_type == DECIMAL_RESULT || hybrid_type == INT_RESULT) 
+  if (cached_result_type == DECIMAL_RESULT || cached_result_type == INT_RESULT) 
   {
     int len0= args[0]->max_length - args[0]->decimals
       - (args[0]->unsigned_flag ? 0 : 1);
@@ -2392,9 +2393,10 @@ Item_func_ifnull::fix_length_and_dec()
   else
     max_length= max(args[0]->max_length, args[1]->max_length);
 
-  switch (hybrid_type) {
+  switch (cached_result_type) {
   case STRING_RESULT:
-    agg_arg_charsets(collation, args, arg_count, MY_COLL_CMP_CONV, 1);
+    if (count_string_result_length(cached_field_type, args, arg_count))
+      return;
     break;
   case DECIMAL_RESULT:
   case REAL_RESULT:
@@ -2407,7 +2409,6 @@ Item_func_ifnull::fix_length_and_dec()
   case IMPOSSIBLE_RESULT:
     DBUG_ASSERT(0);
   }
-  cached_field_type= agg_field_type(args, 2);
 }
 
 
@@ -2421,11 +2422,6 @@ uint Item_func_ifnull::decimal_precision() const
 }
 
 
-enum_field_types Item_func_ifnull::field_type() const 
-{
-  return cached_field_type;
-}
-
 Field *Item_func_ifnull::tmp_table_field(TABLE *table)
 {
   return tmp_table_field_from_field_type(table, 0);
@@ -2499,6 +2495,18 @@ Item_func_ifnull::str_op(String *str)
 }
 
 
+bool Item_func_ifnull::date_op(MYSQL_TIME *ltime, uint fuzzydate)
+{
+  DBUG_ASSERT(fixed == 1);
+  if (!args[0]->get_date(ltime, fuzzydate & ~TIME_FUZZY_DATES))
+    return (null_value= false);
+  if (!args[1]->get_date(ltime, fuzzydate & ~TIME_FUZZY_DATES))
+    return (null_value= false);
+  bzero((char*) ltime,sizeof(*ltime));
+  return null_value= !(fuzzydate & TIME_FUZZY_DATES);
+}
+
+
 /**
   Perform context analysis of an IF item tree.
 
@@ -2587,16 +2595,16 @@ Item_func_if::fix_length_and_dec()
   else
   {
     agg_result_type(&cached_result_type, args+1, 2);
+    cached_field_type= agg_field_type(args + 1, 2);
     if (cached_result_type == STRING_RESULT)
     {
-      if (agg_arg_charsets(collation, args+1, 2, MY_COLL_ALLOW_CONV, 1))
-        return;
+      count_string_result_length(cached_field_type, args + 1, 2);
+      return;
     }
     else
     {
       collation.set(&my_charset_bin);	// Number
     }
-    cached_field_type= agg_field_type(args + 1, 2);
   }
 
   if ((cached_result_type == DECIMAL_RESULT )
@@ -2625,7 +2633,7 @@ uint Item_func_if::decimal_precision() const
 
 
 double
-Item_func_if::val_real()
+Item_func_if::real_op()
 {
   DBUG_ASSERT(fixed == 1);
   Item *arg= args[0]->val_bool() ? args[1] : args[2];
@@ -2635,7 +2643,7 @@ Item_func_if::val_real()
 }
 
 longlong
-Item_func_if::val_int()
+Item_func_if::int_op()
 {
   DBUG_ASSERT(fixed == 1);
   Item *arg= args[0]->val_bool() ? args[1] : args[2];
@@ -2645,7 +2653,7 @@ Item_func_if::val_int()
 }
 
 String *
-Item_func_if::val_str(String *str)
+Item_func_if::str_op(String *str)
 {
   DBUG_ASSERT(fixed == 1);
   Item *arg= args[0]->val_bool() ? args[1] : args[2];
@@ -2658,7 +2666,7 @@ Item_func_if::val_str(String *str)
 
 
 my_decimal *
-Item_func_if::val_decimal(my_decimal *decimal_value)
+Item_func_if::decimal_op(my_decimal *decimal_value)
 {
   DBUG_ASSERT(fixed == 1);
   Item *arg= args[0]->val_bool() ? args[1] : args[2];
@@ -2668,6 +2676,14 @@ Item_func_if::val_decimal(my_decimal *decimal_value)
 }
 
 
+bool Item_func_if::date_op(MYSQL_TIME *ltime, uint fuzzydate)
+{
+  DBUG_ASSERT(fixed == 1);
+  Item *arg= args[0]->val_bool() ? args[1] : args[2];
+  return (null_value= arg->get_date(ltime, fuzzydate));
+}
+
+
 void
 Item_func_nullif::fix_length_and_dec()
 {
@@ -2826,7 +2842,7 @@ Item *Item_func_case::find_item(String *str)
 }
 
 
-String *Item_func_case::val_str(String *str)
+String *Item_func_case::str_op(String *str)
 {
   DBUG_ASSERT(fixed == 1);
   String *res;
@@ -2844,7 +2860,7 @@ String *Item_func_case::val_str(String *str)
 }
 
 
-longlong Item_func_case::val_int()
+longlong Item_func_case::int_op()
 {
   DBUG_ASSERT(fixed == 1);
   char buff[MAX_FIELD_WIDTH];
@@ -2862,7 +2878,7 @@ longlong Item_func_case::val_int()
   return res;
 }
 
-double Item_func_case::val_real()
+double Item_func_case::real_op()
 {
   DBUG_ASSERT(fixed == 1);
   char buff[MAX_FIELD_WIDTH];
@@ -2881,7 +2897,7 @@ double Item_func_case::val_real()
 }
 
 
-my_decimal *Item_func_case::val_decimal(my_decimal *decimal_value)
+my_decimal *Item_func_case::decimal_op(my_decimal *decimal_value)
 {
   DBUG_ASSERT(fixed == 1);
   char buff[MAX_FIELD_WIDTH];
@@ -2901,6 +2917,18 @@ my_decimal *Item_func_case::val_decimal(my_decimal *decimal_value)
 }
 
 
+bool Item_func_case::date_op(MYSQL_TIME *ltime, uint fuzzydate)
+{
+  DBUG_ASSERT(fixed == 1);
+  char buff[MAX_FIELD_WIDTH];
+  String dummy_str(buff, sizeof(buff), default_charset());
+  Item *item= find_item(&dummy_str);
+  if (!item)
+    return (null_value= true);
+  return (null_value= item->get_date(ltime, fuzzydate));
+}
+
+
 bool Item_func_case::fix_fields(THD *thd, Item **ref)
 {
   /*
@@ -2946,7 +2974,10 @@ void Item_func_case::fix_length_and_dec()
   uint found_types= 0;
   if (!(agg= (Item**) sql_alloc(sizeof(Item*)*(ncases+1))))
     return;
-  
+
+  if (else_expr_num == -1 || args[else_expr_num]->maybe_null)
+    maybe_null= 1;
+
   /*
     Aggregate all THEN and ELSE expression types
     and collations when string result
@@ -2959,13 +2990,29 @@ void Item_func_case::fix_length_and_dec()
     agg[nagg++]= args[else_expr_num];
   
   agg_result_type(&cached_result_type, agg, nagg);
-  if ((cached_result_type == STRING_RESULT) &&
-      agg_arg_charsets(collation, agg, nagg, MY_COLL_ALLOW_CONV, 1))
-    return;
-  
   cached_field_type= agg_field_type(agg, nagg);
+
+  if (cached_result_type == STRING_RESULT)
+  {
+    if (count_string_result_length(cached_field_type, agg, nagg))
+      return;
+  }
+  else
+  {
+    max_length= 0;
+    decimals= 0;
+    unsigned_flag= TRUE;
+    for (uint i= 0; i < nagg; i++)
+      agg_num_lengths(agg[i]);
+    if (else_expr_num != -1) 
+      agg_num_lengths(args[else_expr_num]);
+    max_length= my_decimal_precision_to_length(max_length + decimals, decimals,
+                                               unsigned_flag);
+  }
+
+
   /*
-    Aggregate first expression and all THEN expression types
+    Aggregate first expression and all WHEN expression types
     and collations when string comparison
   */
   if (first_expr_num != -1)
@@ -3019,29 +3066,6 @@ void Item_func_case::fix_length_and_dec()
       args[i]->cmp_context= item_cmp_type(left_result_type,
                                           args[i]->result_type());
   }
-
-  if (else_expr_num == -1 || args[else_expr_num]->maybe_null)
-    maybe_null=1;
-  
-  max_length=0;
-  decimals=0;
-  unsigned_flag= TRUE;
-  if (cached_result_type == STRING_RESULT)
-  {
-    for (uint i= 0; i < ncases; i+= 2)
-      agg_str_lengths(args[i + 1]);
-    if (else_expr_num != -1)
-      agg_str_lengths(args[else_expr_num]);
-  }
-  else
-  {
-    for (uint i= 0; i < ncases; i+= 2)
-      agg_num_lengths(args[i + 1]);
-    if (else_expr_num != -1) 
-      agg_num_lengths(args[else_expr_num]);
-    max_length= my_decimal_precision_to_length(max_length + decimals, decimals,
-                                               unsigned_flag);
-  }
 }
 
 
@@ -3149,7 +3173,7 @@ double Item_func_coalesce::real_op()
 }
 
 
-bool Item_func_coalesce::get_date(MYSQL_TIME *ltime,uint fuzzydate)
+bool Item_func_coalesce::date_op(MYSQL_TIME *ltime,uint fuzzydate)
 {
   DBUG_ASSERT(fixed == 1);
   null_value= 0;
@@ -3182,20 +3206,11 @@ my_decimal *Item_func_coalesce::decimal_op(my_decimal *decimal_value)
 void Item_func_coalesce::fix_length_and_dec()
 {
   cached_field_type= agg_field_type(args, arg_count);
-  agg_result_type(&hybrid_type, args, arg_count);
-  Item_result cmp_type;
-  agg_cmp_type(&cmp_type, args, arg_count);
-  ///< @todo let result_type() return TIME_RESULT and remove this special case
-  if (cmp_type == TIME_RESULT)
-  {
-    count_real_length();
-    return;
-  }
-  switch (hybrid_type) {
+  agg_result_type(&cached_result_type, args, arg_count);
+  switch (cached_result_type) {
   case STRING_RESULT:
-    count_only_length();
-    decimals= NOT_FIXED_DEC;
-    agg_arg_charsets(collation, args, arg_count, MY_COLL_ALLOW_CONV, 1);
+    if (count_string_result_length(cached_field_type, args, arg_count))
+      return;          
     break;
   case DECIMAL_RESULT:
     count_decimal_length();
@@ -3204,7 +3219,7 @@ void Item_func_coalesce::fix_length_and_dec()
     count_real_length();
     break;
   case INT_RESULT:
-    count_only_length();
+    count_only_length(args, arg_count);
     decimals= 0;
     break;
   case ROW_RESULT:
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 0ed16c86c0a..37871c31e0b 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -724,24 +724,19 @@ public:
 };
 
 
-class Item_func_coalesce :public Item_func_numhybrid
+class Item_func_coalesce :public Item_func_hybrid_field_type
 {
-protected:
-  enum_field_types cached_field_type;
-  Item_func_coalesce(Item *a, Item *b) :Item_func_numhybrid(a, b) {}
 public:
-  Item_func_coalesce(List<Item> &list) :Item_func_numhybrid(list) {}
+  Item_func_coalesce(Item *a, Item *b) :Item_func_hybrid_field_type(a, b) {}
+  Item_func_coalesce(List<Item> &list) :Item_func_hybrid_field_type(list) {}
   double real_op();
   longlong int_op();
   String *str_op(String *);
   my_decimal *decimal_op(my_decimal *);
+  bool date_op(MYSQL_TIME *ltime,uint fuzzydate);
   void fix_length_and_dec();
-  void find_num_type() {}
-  enum Item_result result_type () const { return hybrid_type; }
   const char *func_name() const { return "coalesce"; }
   table_map not_null_tables() const { return 0; }
-  enum_field_types field_type() const { return cached_field_type; }
-  bool get_date(MYSQL_TIME *ltime,uint fuzzydate);
 };
 
 
@@ -755,7 +750,7 @@ public:
   longlong int_op();
   String *str_op(String *str);
   my_decimal *decimal_op(my_decimal *);
-  enum_field_types field_type() const;
+  bool date_op(MYSQL_TIME *ltime,uint fuzzydate);
   void fix_length_and_dec();
   void update_used_tables()
   {
@@ -768,20 +763,17 @@ public:
 };
 
 
-class Item_func_if :public Item_func
+class Item_func_if :public Item_func_hybrid_field_type
 {
-  enum Item_result cached_result_type;
-  enum_field_types cached_field_type;
 public:
   Item_func_if(Item *a,Item *b,Item *c)
-    :Item_func(a,b,c), cached_result_type(INT_RESULT)
+    :Item_func_hybrid_field_type(a,b,c)
   {}
-  double val_real();
-  longlong val_int();
-  String *val_str(String *str);
-  my_decimal *val_decimal(my_decimal *);
-  enum Item_result result_type () const { return cached_result_type; }
-  enum_field_types field_type() const { return cached_field_type; }
+  bool date_op(MYSQL_TIME *ltime, uint fuzzydate);
+  longlong int_op();
+  double real_op();
+  my_decimal *decimal_op(my_decimal *);
+  String *str_op(String *);
   bool fix_fields(THD *, Item **);
   void fix_length_and_dec();
   void update_used_tables()
@@ -1216,21 +1208,20 @@ public:
   function and only comparators for there result types are used.
 */
 
-class Item_func_case :public Item_func
+class Item_func_case :public Item_func_hybrid_field_type
 {
   int first_expr_num, else_expr_num;
-  enum Item_result cached_result_type, left_result_type;
+  enum Item_result left_result_type;
   String tmp_value;
   uint ncases;
   Item_result cmp_type;
   DTCollation cmp_collation;
-  enum_field_types cached_field_type;
   cmp_item *cmp_items[6]; /* For all result types */
   cmp_item *case_item;
 public:
   Item_func_case(List<Item> &list, Item *first_expr_arg, Item *else_expr_arg)
-    :Item_func(), first_expr_num(-1), else_expr_num(-1),
-    cached_result_type(INT_RESULT), left_result_type(INT_RESULT), case_item(0)
+    :Item_func_hybrid_field_type(), first_expr_num(-1), else_expr_num(-1),
+    left_result_type(INT_RESULT), case_item(0)
   {
     ncases= list.elements;
     if (first_expr_arg)
@@ -1246,10 +1237,11 @@ public:
     set_arguments(list);
     bzero(&cmp_items, sizeof(cmp_items));
   }
-  double val_real();
-  longlong val_int();
-  String *val_str(String *);
-  my_decimal *val_decimal(my_decimal *);
+  double real_op();
+  longlong int_op();
+  String *str_op(String *);
+  my_decimal *decimal_op(my_decimal *);
+  bool date_op(MYSQL_TIME *ltime, uint fuzzydate);
   bool fix_fields(THD *thd, Item **ref);
   void fix_length_and_dec();
   void update_used_tables()
@@ -1260,8 +1252,6 @@ public:
   }
   uint decimal_precision() const;
   table_map not_null_tables() const { return 0; }
-  enum Item_result result_type () const { return cached_result_type; }
-  enum_field_types field_type() const { return cached_field_type; }
   const char *func_name() const { return "case"; }
   virtual void print(String *str, enum_query_type query_type);
   Item *find_item(String *str);
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 9079de6f06e..98da660f8a7 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -594,6 +594,30 @@ void Item_func_numhybrid::fix_num_length_and_dec()
 {}
 
 
+
+/**
+  Count max_length and decimals for temporal functions.
+
+  @param item    Argument array
+  @param nitems  Number of arguments in the array.
+
+  @retval        False on success, true on error.
+*/
+void Item_func::count_datetime_length(Item **item, uint nitems)
+{
+  unsigned_flag= 0;
+  decimals= 0;
+  if (field_type() != MYSQL_TYPE_DATE)
+  {
+    for (uint i= 0; i < nitems; i++)
+      set_if_bigger(decimals, item[i]->decimals);
+  }
+  set_if_smaller(decimals, TIME_SECOND_PART_DIGITS);
+  uint len= decimals ? (decimals + 1) : 0;
+  len+= mysql_temporal_int_part_length(field_type());
+  fix_char_length(len);
+}
+
 /**
   Set max_length/decimals of function if function is fixed point and
   result length/precision depends on argument ones.
@@ -620,14 +644,14 @@ void Item_func::count_decimal_length()
   Set max_length of if it is maximum length of its arguments.
 */
 
-void Item_func::count_only_length()
+void Item_func::count_only_length(Item **item, uint nitems)
 {
   max_length= 0;
   unsigned_flag= 0;
-  for (uint i=0 ; i < arg_count ; i++)
+  for (uint i= 0; i < nitems ; i++)
   {
-    set_if_bigger(max_length, args[i]->max_length);
-    set_if_bigger(unsigned_flag, args[i]->unsigned_flag);
+    set_if_bigger(max_length, item[i]->max_length);
+    set_if_bigger(unsigned_flag, item[i]->unsigned_flag);
   }
 }
 
@@ -663,6 +687,30 @@ void Item_func::count_real_length()
 }
 
 
+/**
+  Calculate max_length and decimals for STRING_RESULT functions.
+
+  @param field_type  Field type.
+  @param items       Argument array.
+  @param nitems      Number of arguments.
+
+  @retval            False on success, true on error.
+*/
+bool Item_func::count_string_result_length(enum_field_types field_type,
+                                           Item **items, uint nitems)
+{
+  if (agg_arg_charsets(collation, items, nitems, MY_COLL_ALLOW_CONV, 1))
+    return true;
+  if (is_temporal_type(field_type))
+    count_datetime_length(items, nitems);
+  else
+  {
+    decimals= NOT_FIXED_DEC; // TODO
+    count_only_length(items, nitems);
+  }
+  return false;
+}
+
 
 void Item_func::signal_divide_by_null()
 {
@@ -735,26 +783,26 @@ void Item_num_op::find_num_type(void)
   {
     count_real_length();
     max_length= float_length(decimals);
-    hybrid_type= REAL_RESULT;
+    cached_result_type= REAL_RESULT;
   }
   else if (r0 == DECIMAL_RESULT || r1 == DECIMAL_RESULT ||
            r0 == TIME_RESULT || r1 == TIME_RESULT)
   {
-    hybrid_type= DECIMAL_RESULT;
+    cached_result_type= DECIMAL_RESULT;
     result_precision();
     fix_decimals();
   }
   else
   {
     DBUG_ASSERT(r0 == INT_RESULT && r1 == INT_RESULT);
-    hybrid_type=INT_RESULT;
+    cached_result_type=INT_RESULT;
     result_precision();
     decimals= 0;
   }
   DBUG_PRINT("info", ("Type: %s",
-             (hybrid_type == REAL_RESULT ? "REAL_RESULT" :
-              hybrid_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
-              hybrid_type == INT_RESULT ? "INT_RESULT" :
+             (cached_result_type == REAL_RESULT ? "REAL_RESULT" :
+              cached_result_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
+              cached_result_type == INT_RESULT ? "INT_RESULT" :
               "--ILLEGAL!!!--")));
   DBUG_VOID_RETURN;
 }
@@ -770,17 +818,17 @@ void Item_func_num1::find_num_type()
 {
   DBUG_ENTER("Item_func_num1::find_num_type");
   DBUG_PRINT("info", ("name %s", func_name()));
-  switch (hybrid_type= args[0]->cast_to_int_type()) {
+  switch (cached_result_type= args[0]->cast_to_int_type()) {
   case INT_RESULT:
     unsigned_flag= args[0]->unsigned_flag;
     break;
   case STRING_RESULT:
   case REAL_RESULT:
-    hybrid_type= REAL_RESULT;
+    cached_result_type= REAL_RESULT;
     max_length= float_length(decimals);
     break;
   case TIME_RESULT:
-    hybrid_type= DECIMAL_RESULT;
+    cached_result_type= DECIMAL_RESULT;
   case DECIMAL_RESULT:
     break;
   case ROW_RESULT:
@@ -788,9 +836,9 @@ void Item_func_num1::find_num_type()
     DBUG_ASSERT(0);
   }
   DBUG_PRINT("info", ("Type: %s",
-                      (hybrid_type == REAL_RESULT ? "REAL_RESULT" :
-                       hybrid_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
-                       hybrid_type == INT_RESULT ? "INT_RESULT" :
+                      (cached_result_type == REAL_RESULT ? "REAL_RESULT" :
+                       cached_result_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
+                       cached_result_type == INT_RESULT ? "INT_RESULT" :
                        "--ILLEGAL!!!--")));
   DBUG_VOID_RETURN;
 }
@@ -810,10 +858,10 @@ void Item_func_numhybrid::fix_length_and_dec()
 }
 
 
-String *Item_func_numhybrid::val_str(String *str)
+String *Item_func_hybrid_result_type::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  switch (hybrid_type) {
+  switch (cached_result_type) {
   case DECIMAL_RESULT:
   {
     my_decimal decimal_value, *val;
@@ -840,6 +888,21 @@ String *Item_func_numhybrid::val_str(String *str)
     break;
   }
   case STRING_RESULT:
+    if (is_temporal_type(field_type()))
+    {
+      MYSQL_TIME ltime;
+      if (date_op(&ltime,
+                  field_type() == MYSQL_TYPE_TIME ? TIME_TIME_ONLY : 0) ||
+          str->alloc(MAX_DATE_STRING_REP_LENGTH))
+      {
+        null_value= 1;
+        return (String *) 0;
+      }
+      ltime.time_type= mysql_type_to_time_type(field_type());
+      str->length(my_TIME_to_str(&ltime, const_cast<char*>(str->ptr()), decimals));
+      str->set_charset(&my_charset_bin);
+      return str;
+    }
     return str_op(&str_value);
   case TIME_RESULT:
   case ROW_RESULT:
@@ -850,10 +913,10 @@ String *Item_func_numhybrid::val_str(String *str)
 }
 
 
-double Item_func_numhybrid::val_real()
+double Item_func_hybrid_result_type::val_real()
 {
   DBUG_ASSERT(fixed == 1);
-  switch (hybrid_type) {
+  switch (cached_result_type) {
   case DECIMAL_RESULT:
   {
     my_decimal decimal_value, *val;
@@ -872,6 +935,18 @@ double Item_func_numhybrid::val_real()
     return real_op();
   case STRING_RESULT:
   {
+    if (is_temporal_type(field_type()))
+    {
+      MYSQL_TIME ltime;
+      if (date_op(&ltime,
+                  field_type() == MYSQL_TYPE_TIME ? TIME_TIME_ONLY : 0 ))
+      {
+        null_value= 1;
+        return 0;
+      }
+      ltime.time_type= mysql_type_to_time_type(field_type());
+      return TIME_to_double(&ltime);
+    }
     char *end_not_used;
     int err_not_used;
     String *res= str_op(&str_value);
@@ -887,10 +962,10 @@ double Item_func_numhybrid::val_real()
 }
 
 
-longlong Item_func_numhybrid::val_int()
+longlong Item_func_hybrid_result_type::val_int()
 {
   DBUG_ASSERT(fixed == 1);
-  switch (hybrid_type) {
+  switch (cached_result_type) {
   case DECIMAL_RESULT:
   {
     my_decimal decimal_value, *val;
@@ -906,6 +981,18 @@ longlong Item_func_numhybrid::val_int()
     return (longlong) rint(real_op());
   case STRING_RESULT:
   {
+    if (is_temporal_type(field_type()))
+    {
+      MYSQL_TIME ltime;
+      if (date_op(&ltime,
+                  field_type() == MYSQL_TYPE_TIME ? TIME_TIME_ONLY : 0))
+      {
+        null_value= 1;
+        return 0;
+      }
+      ltime.time_type= mysql_type_to_time_type(field_type());
+      return TIME_to_ulonglong(&ltime);
+    }
     int err_not_used;
     String *res;
     if (!(res= str_op(&str_value)))
@@ -924,11 +1011,11 @@ longlong Item_func_numhybrid::val_int()
 }
 
 
-my_decimal *Item_func_numhybrid::val_decimal(my_decimal *decimal_value)
+my_decimal *Item_func_hybrid_result_type::val_decimal(my_decimal *decimal_value)
 {
   my_decimal *val= decimal_value;
   DBUG_ASSERT(fixed == 1);
-  switch (hybrid_type) {
+  switch (cached_result_type) {
   case DECIMAL_RESULT:
     val= decimal_op(decimal_value);
     break;
@@ -946,6 +1033,19 @@ my_decimal *Item_func_numhybrid::val_decimal(my_decimal *decimal_value)
   }
   case STRING_RESULT:
   {
+    if (is_temporal_type(field_type()))
+    {
+      MYSQL_TIME ltime;
+      if (date_op(&ltime,
+                  field_type() == MYSQL_TYPE_TIME ? TIME_TIME_ONLY : 0))
+      {
+        my_decimal_set_zero(decimal_value);
+        null_value= 1;
+        return 0;
+      }
+      ltime.time_type= mysql_type_to_time_type(field_type());
+      return date2my_decimal(&ltime, decimal_value);
+    }
     String *res;
     if (!(res= str_op(&str_value)))
       return NULL;
@@ -963,6 +1063,62 @@ my_decimal *Item_func_numhybrid::val_decimal(my_decimal *decimal_value)
 }
 
 
+bool Item_func_hybrid_result_type::get_date(MYSQL_TIME *ltime, uint fuzzydate)
+{
+  DBUG_ASSERT(fixed == 1);
+  switch (cached_result_type) {
+  case DECIMAL_RESULT:
+  {
+    my_decimal value, *res;
+    if (!(res= decimal_op(&value)) ||
+        decimal_to_datetime_with_warn(res, ltime, fuzzydate,
+                                      field_name_or_null()))
+      goto err;
+    break;
+  }
+  case INT_RESULT:
+  {
+    longlong value= int_op();
+    if (null_value || int_to_datetime_with_warn(value, ltime, fuzzydate,
+                                                field_name_or_null()))
+      goto err;
+    break;
+  }
+  case REAL_RESULT:
+  {
+    double value= real_op();
+    if (null_value || double_to_datetime_with_warn(value, ltime, fuzzydate,
+                                                   field_name_or_null()))
+      goto err;
+    break;
+  }
+  case STRING_RESULT:
+  {
+    if (is_temporal_type(field_type()))
+      return date_op(ltime, fuzzydate);
+    char buff[40];
+    String tmp(buff,sizeof(buff), &my_charset_bin),*res;
+    if (!(res= str_op(&tmp)) ||
+        str_to_datetime_with_warn(res->ptr(), res->length(),
+                                  ltime, fuzzydate) <= MYSQL_TIMESTAMP_ERROR)
+      goto err;
+    break;
+     break;
+  }
+  case ROW_RESULT:
+  case TIME_RESULT:
+  case IMPOSSIBLE_RESULT:
+    DBUG_ASSERT(0);
+  }
+
+  return (null_value= 0);
+
+err:
+  bzero(ltime, sizeof(*ltime));
+  return null_value|= !(fuzzydate & TIME_FUZZY_DATES);  
+}
+
+
 void Item_func_signed::print(String *str, enum_query_type query_type)
 {
   str->append(STRING_WITH_LEN("cast("));
@@ -1471,7 +1627,7 @@ void Item_func_div::fix_length_and_dec()
   DBUG_ENTER("Item_func_div::fix_length_and_dec");
   prec_increment= current_thd->variables.div_precincrement;
   Item_num_op::fix_length_and_dec();
-  switch (hybrid_type) {
+  switch (cached_result_type) {
   case REAL_RESULT:
   {
     decimals=max(args[0]->decimals,args[1]->decimals)+prec_increment;
@@ -1487,7 +1643,7 @@ void Item_func_div::fix_length_and_dec()
     break;
   }
   case INT_RESULT:
-    hybrid_type= DECIMAL_RESULT;
+    cached_result_type= DECIMAL_RESULT;
     DBUG_PRINT("info", ("Type changed: DECIMAL_RESULT"));
     result_precision();
     break;
@@ -1670,7 +1826,7 @@ void Item_func_neg::fix_length_and_dec()
     Use val() to get value as arg_type doesn't mean that item is
     Item_int or Item_real due to existence of Item_param.
   */
-  if (hybrid_type == INT_RESULT && args[0]->const_item())
+  if (cached_result_type == INT_RESULT && args[0]->const_item())
   {
     longlong val= args[0]->val_int();
     if ((ulonglong) val >= (ulonglong) LONGLONG_MIN &&
@@ -1681,7 +1837,7 @@ void Item_func_neg::fix_length_and_dec()
         Ensure that result is converted to DECIMAL, as longlong can't hold
         the negated number
       */
-      hybrid_type= DECIMAL_RESULT;
+      cached_result_type= DECIMAL_RESULT;
       DBUG_PRINT("info", ("Type changed: DECIMAL_RESULT"));
     }
   }
@@ -1968,11 +2124,11 @@ void Item_func_int_val::find_num_type()
 {
   DBUG_ENTER("Item_func_int_val::find_num_type");
   DBUG_PRINT("info", ("name %s", func_name()));
-  switch (hybrid_type= args[0]->cast_to_int_type())
+  switch (cached_result_type= args[0]->cast_to_int_type())
   {
   case STRING_RESULT:
   case REAL_RESULT:
-    hybrid_type= REAL_RESULT;
+    cached_result_type= REAL_RESULT;
     max_length= float_length(decimals);
     break;
   case INT_RESULT:
@@ -1985,12 +2141,12 @@ void Item_func_int_val::find_num_type()
     if ((args[0]->max_length - args[0]->decimals) >=
         (DECIMAL_LONGLONG_DIGITS - 2))
     {
-      hybrid_type= DECIMAL_RESULT;
+      cached_result_type= DECIMAL_RESULT;
     }
     else
     {
       unsigned_flag= args[0]->unsigned_flag;
-      hybrid_type= INT_RESULT;
+      cached_result_type= INT_RESULT;
     }
     break;
   case ROW_RESULT:
@@ -1998,9 +2154,9 @@ void Item_func_int_val::find_num_type()
     DBUG_ASSERT(0);
   }
   DBUG_PRINT("info", ("Type: %s",
-                      (hybrid_type == REAL_RESULT ? "REAL_RESULT" :
-                       hybrid_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
-                       hybrid_type == INT_RESULT ? "INT_RESULT" :
+                      (cached_result_type == REAL_RESULT ? "REAL_RESULT" :
+                       cached_result_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
+                       cached_result_type == INT_RESULT ? "INT_RESULT" :
                        "--ILLEGAL!!!--")));
 
   DBUG_VOID_RETURN;
@@ -2115,10 +2271,10 @@ void Item_func_round::fix_length_and_dec()
     if (args[0]->result_type() == DECIMAL_RESULT)
     {
       max_length++;
-      hybrid_type= DECIMAL_RESULT;
+      cached_result_type= DECIMAL_RESULT;
     }
     else
-      hybrid_type= REAL_RESULT;
+      cached_result_type= REAL_RESULT;
     return;
   }
 
@@ -2136,14 +2292,14 @@ void Item_func_round::fix_length_and_dec()
   {
     decimals= min(decimals_to_set, NOT_FIXED_DEC);
     max_length= float_length(decimals);
-    hybrid_type= REAL_RESULT;
+    cached_result_type= REAL_RESULT;
     return;
   }
   
   switch (args[0]->result_type()) {
   case REAL_RESULT:
   case STRING_RESULT:
-    hybrid_type= REAL_RESULT;
+    cached_result_type= REAL_RESULT;
     decimals= min(decimals_to_set, NOT_FIXED_DEC);
     max_length= float_length(decimals);
     break;
@@ -2153,14 +2309,14 @@ void Item_func_round::fix_length_and_dec()
       int length_can_increase= test(!truncate && (val1 < 0) && !val1_unsigned);
       max_length= args[0]->max_length + length_can_increase;
       /* Here we can keep INT_RESULT */
-      hybrid_type= INT_RESULT;
+      cached_result_type= INT_RESULT;
       decimals= 0;
       break;
     }
     /* fall through */
   case DECIMAL_RESULT:
   {
-    hybrid_type= DECIMAL_RESULT;
+    cached_result_type= DECIMAL_RESULT;
     decimals_to_set= min(DECIMAL_MAX_SCALE, decimals_to_set);
     int decimals_delta= args[0]->decimals - decimals_to_set;
     int precision= args[0]->decimal_precision();
diff --git a/sql/item_func.h b/sql/item_func.h
index c4b21b6287d..44070354990 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -148,9 +148,12 @@ public:
   void print_op(String *str, enum_query_type query_type);
   void print_args(String *str, uint from, enum_query_type query_type);
   virtual void fix_num_length_and_dec();
-  void count_only_length();
+  void count_only_length(Item **item, uint nitems);
   void count_real_length();
   void count_decimal_length();
+  void count_datetime_length(Item **item, uint nitems);
+  bool count_string_result_length(enum_field_types field_type,
+                                  Item **item, uint nitems);
   inline bool get_arg0_date(MYSQL_TIME *ltime, uint fuzzy_date)
   {
     return (null_value=args[0]->get_date(ltime, fuzzy_date));
@@ -327,38 +330,33 @@ public:
 };
 
 
-class Item_func_numhybrid: public Item_func
+class Item_func_hybrid_result_type: public Item_func
 {
 protected:
-  Item_result hybrid_type;
+  Item_result cached_result_type;
+
 public:
-  Item_func_numhybrid() :Item_func(), hybrid_type(REAL_RESULT)
+  Item_func_hybrid_result_type() :Item_func(), cached_result_type(REAL_RESULT)
   {}
-  Item_func_numhybrid(Item *a) :Item_func(a), hybrid_type(REAL_RESULT)
+  Item_func_hybrid_result_type(Item *a) :Item_func(a), cached_result_type(REAL_RESULT)
   {}
-  Item_func_numhybrid(Item *a,Item *b)
-    :Item_func(a,b), hybrid_type(REAL_RESULT)
+  Item_func_hybrid_result_type(Item *a,Item *b)
+    :Item_func(a,b), cached_result_type(REAL_RESULT)
   {}
-  Item_func_numhybrid(List<Item> &list)
-    :Item_func(list), hybrid_type(REAL_RESULT)
+  Item_func_hybrid_result_type(Item *a,Item *b,Item *c)
+    :Item_func(a,b,c), cached_result_type(REAL_RESULT)
+  {}
+  Item_func_hybrid_result_type(List<Item> &list)
+    :Item_func(list), cached_result_type(REAL_RESULT)
   {}
 
-  enum Item_result result_type () const { return hybrid_type; }
-  void fix_length_and_dec();
-  void fix_num_length_and_dec();
-  virtual void find_num_type()= 0; /* To be called from fix_length_and_dec */
-
-  inline void fix_decimals()
-  {
-    DBUG_ASSERT(result_type() == DECIMAL_RESULT);
-    if (decimals == NOT_FIXED_DEC)
-      set_if_smaller(decimals, max_length - 1);
-  }
+  enum Item_result result_type () const { return cached_result_type; }
 
   double val_real();
   longlong val_int();
   my_decimal *val_decimal(my_decimal *);
   String *val_str(String*str);
+  bool get_date(MYSQL_TIME *res, uint fuzzy_date);
 
   /**
      @brief Performs the operation that this functions implements when the
@@ -395,9 +393,75 @@ public:
      @return The result of the operation.
   */
   virtual String *str_op(String *)= 0;
-  bool is_null() { update_null_value(); return null_value; }
+
+  /**
+     @brief Performs the operation that this functions implements when
+     field type is a temporal type.
+     @return The result of the operation.
+  */
+  virtual bool date_op(MYSQL_TIME *res, uint fuzzy_date)= 0;
+
 };
 
+
+
+class Item_func_hybrid_field_type :public Item_func_hybrid_result_type
+{
+protected:
+  enum_field_types cached_field_type;
+public:
+  Item_func_hybrid_field_type()
+    :Item_func_hybrid_result_type(), cached_field_type(MYSQL_TYPE_DOUBLE)
+  {}
+  Item_func_hybrid_field_type(Item *a, Item *b)
+    :Item_func_hybrid_result_type(a, b), cached_field_type(MYSQL_TYPE_DOUBLE)
+  {}
+  Item_func_hybrid_field_type(Item *a, Item *b, Item *c)
+    :Item_func_hybrid_result_type(a, b, c),
+    cached_field_type(MYSQL_TYPE_DOUBLE)
+  {}
+  Item_func_hybrid_field_type(List<Item> &list)
+    :Item_func_hybrid_result_type(list),
+    cached_field_type(MYSQL_TYPE_DOUBLE)
+  {}
+  enum_field_types field_type() const { return cached_field_type; }
+};
+
+
+
+class Item_func_numhybrid: public Item_func_hybrid_result_type
+{
+protected:
+
+  inline void fix_decimals()
+  {
+    DBUG_ASSERT(result_type() == DECIMAL_RESULT);
+    if (decimals == NOT_FIXED_DEC)
+      set_if_smaller(decimals, max_length - 1);
+  }
+
+public:
+  Item_func_numhybrid() :Item_func_hybrid_result_type()
+  {}
+  Item_func_numhybrid(Item *a) :Item_func_hybrid_result_type(a)
+  {}
+  Item_func_numhybrid(Item *a,Item *b)
+    :Item_func_hybrid_result_type(a,b)
+  {}
+  Item_func_numhybrid(Item *a,Item *b,Item *c)
+    :Item_func_hybrid_result_type(a,b,c)
+  {}
+  Item_func_numhybrid(List<Item> &list)
+    :Item_func_hybrid_result_type(list)
+  {}
+  void fix_length_and_dec();
+  void fix_num_length_and_dec();
+  virtual void find_num_type()= 0; /* To be called from fix_length_and_dec */
+  String *str_op(String *str) { DBUG_ASSERT(0); return 0; }
+  bool date_op(MYSQL_TIME *ltime, uint fuzzydate) { DBUG_ASSERT(0); return true; }
+};
+
+
 /* function where type of result detected by first argument */
 class Item_func_num1: public Item_func_numhybrid
 {
@@ -407,7 +471,6 @@ public:
 
   void fix_num_length_and_dec();
   void find_num_type();
-  String *str_op(String *str) { DBUG_ASSERT(0); return 0; }
 };
 
 
@@ -424,7 +487,6 @@ class Item_num_op :public Item_func_numhybrid
   }
 
   void find_num_type();
-  String *str_op(String *str) { DBUG_ASSERT(0); return 0; }
 };
 
 
diff --git a/sql/item_timefunc.h b/sql/item_timefunc.h
index b17e1c794ee..b0245e6f743 100644
--- a/sql/item_timefunc.h
+++ b/sql/item_timefunc.h
@@ -372,9 +372,11 @@ public:
     max_length=17 + (decimals ? decimals + 1 : 0);
     set_persist_maybe_null(1);
   }
-  void find_num_type() { hybrid_type= decimals ? DECIMAL_RESULT : INT_RESULT; }
+  void find_num_type()
+  { cached_result_type= decimals ? DECIMAL_RESULT : INT_RESULT; }
   double real_op() { DBUG_ASSERT(0); return 0; }
   String *str_op(String *str) { DBUG_ASSERT(0); return 0; }
+  bool date_op(MYSQL_TIME *ltime, uint fuzzydate) { DBUG_ASSERT(0); return true; }
 };
 
 
@@ -451,12 +453,8 @@ public:
   { 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 };
-
     set_persist_maybe_null(1);
-    max_length= max_time_type_width[mysql_type_to_time_type(field_type())+2];
+    max_length= mysql_temporal_int_part_length(field_type());
     if (decimals)
     {
       if (decimals == NOT_FIXED_DEC)
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 1bf5816430c..913ab66a843 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -930,6 +930,17 @@ mysql_type_to_time_type(enum enum_field_types mysql_type)
   }
 }
 
+
+static inline uint
+mysql_temporal_int_part_length(enum enum_field_types mysql_type)
+{
+  static uint max_time_type_width[5]=
+  { MAX_DATETIME_WIDTH, MAX_DATETIME_WIDTH, MAX_DATE_WIDTH,
+    MAX_DATETIME_WIDTH, MIN_TIME_WIDTH };
+  return max_time_type_width[mysql_type_to_time_type(mysql_type)+2];
+}
+
+
 #include "sql_list.h"
 #include "sql_map.h"
 #include "handler.h"