MDEV-12775 Reuse data type aggregation code for hybrid functions and …

…UNION

Introducing a new class Type_holder (used internally in sql_union.cc),
to reuse exactly the same data type attribute aggregation Type_handler API
for hybrid functions and UNION.

This fixes a number of bugs in UNION:

- MDEV-9495 Wrong field type for a UNION of a signed and an unsigned INT expression
- MDEV-9497 UNION and COALESCE produce different field types for DECIMAL+INT
- MDEV-12594 UNION between fixed length double columns does not always preserve scale
- MDEV-12595 UNION converts INT to BIGINT
- MDEV-12599 UNION is not symmetric when mixing INT and CHAR

Details:

- sql_union.cc: Reusing attribute aggregation for UNION.
  Adding new methods:
  * st_select_lex_unit::join_union_type_handlers()
  * st_select_lex_unit::join_union_type_attributes()
  * st_select_lex_unit::join_union_item_types()
  Removing the old join_types()-based code.

- Changing Type_handler::Item_hybrid_func_fix_attributes()
  to accept "name", Type_handler_hybrid_field_type, Type_all_attributes
  as three separate parameters instead of a single Item_hybrid_func parameter,
  to make it possible to pass both Item_hybrid_func and Type_holder.

- Moving the former special GEOMETRY and ENUM/SET attribute aggregation code
  from Item_type_holder::join_types() to
  * Type_handler_typelib::Item_hybrid_func_fix_attributes().
  * Type_handler_geometry::Item_hybrid_func_fix_attrubutes().
  This makes GEOMETRY/ENUM/SET symmetric with all other data types
  (from the UNION point of view).
  Removing Item_type_holder::join_types() and Item_type_holder::get_full_info().

- Adding new methods into Type_all_attributes:
  * Type_all_attributes::set_geometry_type() and
    Item_hybrid_func::set_geometry_type().
  * Adding Type_all_attributes::get_typelib().
  * Adding Type_all_attributes::set_typelib().

- Adding Type_handler_typelib as a common parent for
  Type_handler_enum and Type_handler_set, to avoid code duplication: they have
  already had two common methods, and we're adding one more shared method.

- Adding Type_all_attributes::set_maybe_null(), as some type handlers
  may want to set maybe_null (e.g. Type_handler_geometry) during data type
  attribute aggregation.

- Changing Type_geometry_attributes() to accept Type_handler
  and Type_all_attributes as two separate parameters, instead
  of a single Item parameter, to make it possible to pass Type_holder.

- Adding Item_args::add_argument().

- Moving Item_args::alloc_arguments() from "protected" to "public".

- Moving Item_type_holder::Item_type_holder() from item.cc to item.h, as
  now it's very simple.
  Btw, this constructor should probably be eventually removed.
  It's now used only in sql_show.cc, which could be modified to use
  Item_return_decimal (for symmetry with Item_return_xxx created for all
  other data types). Or, another option: remove all Item_return_xxx and
  use Item_type_holder for all data types instead.

- storage/tokudb/mysql-test/tokudb/r/type_float.result
  Recording new results (MDEV-12594).

- mysql-test/r/cte_recursive.result
  Recording new results (MDEV-9497)

- mysql-test/r/subselect*.result
  Recording new results (MDEV-12595)

- mysql-test/r/metadata.result
  Recording new results (MDEV-9495)

- mysql-test/r/temp_table.result
  Recording new results (MDEV-12594)

- mysql-test/r/type_float.result
  Recording new results (MDEV-12594)

mysql-test/r/cte_recursive.result

@@ -130,7 +130,7 @@ select t2.a+1 from t1,t2 where t1.a=t2.a
 select * from t1;
 show columns from v1;
 Field	Type	Null	Key	Default	Extra
-a	bigint(20)	YES		NULL	
+a	bigint(12)	YES		NULL	
 # WITH RECURSIVE : types of t1 columns are determined by anchor parts 
 create view v2 as
 with recursive

mysql-test/r/metadata.result

@@ -147,7 +147,7 @@ id	data	data
 2	female	no
 select t1.id from t1 union select t2.id from t2;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
-def				id	id	1	4	1	Y	32768	0	63
+def				id	id	246	4	1	Y	32768	0	63
 id
 1
 2
@@ -168,12 +168,12 @@ def			aaa	@arg00	@arg00	8	20	1	Y	32768	0	63
 1
 select 1 union select 1;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
-def				1	1	3	11	1	N	32769	0	63
+def				1	1	3	1	1	N	32769	0	63
 1
 1
 select * from (select 1 union select 1) aaa;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
-def			aaa	1	1	3	11	1	N	32769	0	63
+def			aaa	1	1	3	1	1	N	32769	0	63
 1
 1
 drop table t1;

mysql-test/r/subselect.result

@@ -1260,7 +1260,7 @@ a
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` bigint(20) NOT NULL
+  `a` int(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 (a int);

mysql-test/r/subselect_no_exists_to_in.result

@@ -1264,7 +1264,7 @@ a
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` bigint(20) NOT NULL
+  `a` int(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 (a int);

mysql-test/r/subselect_no_mat.result

@@ -1267,7 +1267,7 @@ a
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` bigint(20) NOT NULL
+  `a` int(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 (a int);

mysql-test/r/subselect_no_opts.result

@@ -1263,7 +1263,7 @@ a
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` bigint(20) NOT NULL
+  `a` int(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 (a int);

mysql-test/r/subselect_no_scache.result

@@ -1266,7 +1266,7 @@ a
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` bigint(20) NOT NULL
+  `a` int(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 (a int);

mysql-test/r/subselect_no_semijoin.result

@@ -1263,7 +1263,7 @@ a
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` bigint(20) NOT NULL
+  `a` int(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 (a int);

mysql-test/r/temp_table.result

@@ -181,20 +181,20 @@ CREATE TABLE t2 ( c FLOAT(30,18) );
 INSERT INTO t2 VALUES( 123456 );
 SELECT AVG( c ) FROM t1 UNION SELECT 1;
 AVG( c )
-12139
-1
+12139.000000000000000000
+1.000000000000000000
 SELECT 1 UNION SELECT AVG( c ) FROM t1;
 1
-1
-12139
+1.000000000000000000
+12139.000000000000000000
 SELECT 1 UNION SELECT * FROM t2 UNION SELECT 1;
 1
-1
-123456
+1.000000000000000000
+123456.000000000000000000
 SELECT c/1 FROM t1 UNION SELECT 1;
 c/1
-12139
-1
+12139.000000000000000000
+1.000000000000000000
 DROP TABLE t1, t2;
 create temporary table t1 (a int);
 insert into t1 values (4711);

mysql-test/r/type_float.result

@@ -232,12 +232,12 @@ insert into t2 values ("1.23456780");
 create table t3 select * from t2 union select * from t1;
 select * from t3;
 d
-1.2345678
-100000000
+1.234567800
+100000000.000000000
 show create table t3;
 Table	Create Table
 t3	CREATE TABLE `t3` (
-  `d` double DEFAULT NULL
+  `d` double(18,9) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1, t2, t3;
 create table t1 select  105213674794682365.00 + 0.0 x;

mysql-test/r/union.result

@@ -852,7 +852,7 @@ select * from t1;
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `1` int(11) NOT NULL DEFAULT 0
+  `1` int(2) NOT NULL DEFAULT 0
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 select _latin1"test" union select _latin2"testt" ;
@@ -1608,7 +1608,7 @@ NULL	binary(0)	YES		NULL
 CREATE TABLE t5 SELECT NULL UNION SELECT NULL;
 DESC t5;
 Field	Type	Null	Key	Default	Extra
-NULL	binary(0)	YES		NULL	
+NULL	null	YES		NULL	
 CREATE TABLE t6 
 SELECT * FROM (SELECT * FROM (SELECT NULL)a) b UNION SELECT a FROM t1;
 DESC t6;
@@ -2195,16 +2195,223 @@ CREATE OR REPLACE TABLE t1 AS SELECT 1 UNION SELECT 1;
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `1` int(11) NOT NULL DEFAULT 0
+  `1` int(1) NOT NULL DEFAULT 0
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 CREATE OR REPLACE TABLE t1 AS SELECT * FROM (SELECT 1 UNION SELECT 1) AS t0;
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `1` int(11) NOT NULL DEFAULT 0
+  `1` int(1) NOT NULL DEFAULT 0
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+#
+# MDEV-9495 Wrong field type for a UNION of a signed and an unsigned INT expression
+#
+CREATE TABLE t1 (a INT, b INT UNSIGNED);
+INSERT INTO t1 VALUES (0x7FFFFFFF,0xFFFFFFFF);
+CREATE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `a` decimal(10,0) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT * FROM t2 ORDER BY a;
+a
+2147483647
+4294967295
+DROP TABLE t2;
+CREATE TABLE t2 AS SELECT COALESCE(a,b), COALESCE(b,a) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `COALESCE(a,b)` decimal(10,0) DEFAULT NULL,
+  `COALESCE(b,a)` decimal(10,0) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT * FROM t2;
+COALESCE(a,b)	COALESCE(b,a)
+2147483647	4294967295
+DROP TABLE t2;
+DROP TABLE t1;
+#
+# MDEV-9497 UNION and COALESCE produce different field types for DECIMAL+INT
+#
+CREATE TABLE t1 AS SELECT COALESCE(10.1,CAST(10 AS UNSIGNED)) AS a;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(3,1) NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE OR REPLACE TABLE t1 AS SELECT 10.1 AS a UNION SELECT CAST(10 AS UNSIGNED);
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(3,1) NOT NULL DEFAULT 0.0
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 #
+# MDEV-12594 UNION between fixed length double columns does not always preserve scale
+#
+CREATE TABLE t1 (a FLOAT(20,4), b FLOAT(20,3), c FLOAT(20,4));
+INSERT INTO t1 VALUES (1111,2222,3333);
+CREATE TABLE t2 AS SELECT a FROM t1 UNION SELECT a FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `a` float(20,4) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE OR REPLACE TABLE t2 SELECT a FROM t1 UNION SELECT c FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `a` float(20,4) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE OR REPLACE TABLE t2 SELECT b FROM t1 UNION SELECT b FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `b` float(20,3) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE OR REPLACE TABLE t2 SELECT c FROM t1 UNION SELECT c FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `c` float(20,4) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE OR REPLACE TABLE t2 SELECT c FROM t1 UNION SELECT a FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `c` float(20,4) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE OR REPLACE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `a` float(21,4) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE OR REPLACE TABLE t2 AS SELECT b FROM t1 UNION SELECT a FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `b` float(21,4) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+# Corner case
+CREATE TABLE t1 (a FLOAT(255,4), b FLOAT(255,3));
+INSERT INTO t1 VALUES (1111,2222);
+CREATE OR REPLACE TABLE t2 AS SELECT b FROM t1 UNION SELECT a FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `b` float(255,4) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+#
+# MDEV-12595 UNION converts INT to BIGINT
+#
+CREATE TABLE t1 AS SELECT
+1,
+-1,
+COALESCE(1,1),
+COALESCE(-1,-1),
+COALESCE(1,-1),
+COALESCE(-1,1);
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `1` int(1) NOT NULL,
+  `-1` int(2) NOT NULL,
+  `COALESCE(1,1)` int(1) NOT NULL,
+  `COALESCE(-1,-1)` int(2) NOT NULL,
+  `COALESCE(1,-1)` int(2) NOT NULL,
+  `COALESCE(-1,1)` int(2) NOT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT 1 AS c1,1 AS c2,-1 AS c3,-1 AS c4 UNION SELECT 1,-1,1,-1;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` int(1) NOT NULL DEFAULT 0,
+  `c2` int(2) NOT NULL DEFAULT 0,
+  `c3` int(2) NOT NULL DEFAULT 0,
+  `c4` int(2) NOT NULL DEFAULT 0
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+#
+# MDEV-12599 UNION is not symmetric when mixing INT and CHAR
+#
+CREATE OR REPLACE TABLE t1 AS SELECT 1 AS c1, 'a' AS c2 UNION SELECT 'a', 1;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(1) NOT NULL DEFAULT '',
+  `c2` varchar(1) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE OR REPLACE TABLE t1 AS SELECT 11112222 AS c1, 'a' AS c2 UNION SELECT 'a', 11112222;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(8) NOT NULL DEFAULT '',
+  `c2` varchar(8) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE OR REPLACE TABLE t1 AS SELECT 111122223333 AS c1, 'a' AS c2 UNION SELECT 'a', 111122223333;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(12) NOT NULL DEFAULT '',
+  `c2` varchar(12) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE OR REPLACE TABLE t1 AS SELECT 1111222233334444 AS c1, 'a' AS c2 UNION SELECT 'a', 1111222233334444;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` varchar(16) NOT NULL DEFAULT '',
+  `c2` varchar(16) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE TABLE t1 (a INT(3), b VARCHAR(1));
+CREATE TABLE t2 AS SELECT a,b FROM t1 UNION SELECT b,a FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `a` varchar(11) DEFAULT NULL,
+  `b` varchar(11) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+CREATE TABLE t1 (a BIGINT(3), b VARCHAR(1));
+CREATE TABLE t2 AS SELECT a,b FROM t1 UNION SELECT b,a FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `a` varchar(20) DEFAULT NULL,
+  `b` varchar(20) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+CREATE TABLE t1 (a BIGINT(12), b VARCHAR(1));
+CREATE TABLE t2 AS SELECT a,b FROM t1 UNION SELECT b,a FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `a` varchar(20) DEFAULT NULL,
+  `b` varchar(20) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+#
 # End of 10.3 tests
 #