Bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were optimized

away.

Additional fix for bug#22331. Now Item_field prints its value in the case of
the const field.

mysql-test/r/explain.result

@@ -64,7 +64,7 @@ explain extended select * from v1 where f2=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 Warnings:
-Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` where 1
+Note	1003	select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
 explain extended select * from t1 where 0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
@@ -74,7 +74,7 @@ explain extended select * from t1 where 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 Warnings:
-Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` where 1
+Note	1003	select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
 explain extended select * from t1 having 0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible HAVING
@@ -84,6 +84,6 @@ explain extended select * from t1 having 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 Warnings:
-Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` having 1
+Note	1003	select '1' AS `f1`,'1' AS `f2` from `test`.`t1` having 1
 drop view v1;
 drop table t1;

mysql-test/r/func_default.result

@@ -8,7 +8,7 @@ explain extended select default(str), default(strnull), default(intg), default(r
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 Warnings:
-Note	1003	select default(`test`.`t1`.`str`) AS `default(str)`,default(`test`.`t1`.`strnull`) AS `default(strnull)`,default(`test`.`t1`.`intg`) AS `default(intg)`,default(`test`.`t1`.`rel`) AS `default(rel)` from `test`.`t1`
+Note	1003	select default('') AS `default(str)`,default('') AS `default(strnull)`,default('0') AS `default(intg)`,default('0') AS `default(rel)` from `test`.`t1`
 select * from t1 where str <> default(str);
 str	strnull	intg	rel
 		0	0

mysql-test/r/func_regexp.result

@@ -40,7 +40,7 @@ explain extended select * from t1 where xxx regexp('is a test of some long text
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 Warnings:
-Note	1003	select `test`.`t1`.`xxx` AS `xxx` from `test`.`t1` where (`test`.`t1`.`xxx` regexp _latin1'is a test of some long text to')
+Note	1003	select 'this is a test of some long text to see what happens' AS `xxx` from `test`.`t1` where ('this is a test of some long text to see what happens' regexp _latin1'is a test of some long text to')
 select * from t1 where xxx regexp('is a test of some long text to ');
 xxx
 this is a test of some long text to see what happens

mysql-test/r/func_str.result

@@ -1089,12 +1089,12 @@ explain extended select encode(f1,'zxcv') as 'enc' from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select encode(`test`.`t1`.`f1`,'zxcv') AS `enc` from `test`.`t1`
+Note	1003	select encode('','zxcv') AS `enc` from `test`.`t1`
 explain extended select decode(f1,'zxcv') as 'enc' from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select decode(`test`.`t1`.`f1`,'zxcv') AS `enc` from `test`.`t1`
+Note	1003	select decode('','zxcv') AS `enc` from `test`.`t1`
 drop table t1;
 End of 4.1 tests
 create table t1 (d decimal default null);
@@ -1158,7 +1158,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	const	PRIMARY	PRIMARY	12	const	1	Using index
 1	SIMPLE	t1	ref	code	code	13	const	3	Using where; Using index
 Warnings:
-Note	1003	select `test`.`t1`.`code` AS `code`,`test`.`t2`.`id` AS `id` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`code` = _latin1'a12') and (length(`test`.`t1`.`code`) = 5))
+Note	1003	select `test`.`t1`.`code` AS `code`,'a12' AS `id` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`code` = _latin1'a12') and (length(`test`.`t1`.`code`) = 5))
 DROP TABLE t1,t2;
 select locate('he','hello',-2);
 locate('he','hello',-2)

mysql-test/r/func_test.result

@@ -87,7 +87,7 @@ explain extended select - a from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 Warnings:
-Note	1003	select -(`test`.`t1`.`a`) AS `- a` from `test`.`t1`
+Note	1003	select -('1') AS `- a` from `test`.`t1`
 drop table t1;
 select 5 between 0 and 10 between 0 and 1,(5 between 0 and 10) between 0 and 1;
 5 between 0 and 10 between 0 and 1	(5 between 0 and 10) between 0 and 1

mysql-test/r/having.result

@@ -12,7 +12,7 @@ explain extended select count(a) as b from t1 where a=0 having b >=0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
-Note	1003	select count(`test`.`t1`.`a`) AS `b` from `test`.`t1` where 0 having (`b` >= 0)
+Note	1003	select count('0') AS `b` from `test`.`t1` where 0 having (`b` >= 0)
 drop table t1;
 CREATE TABLE t1 (
 raw_id int(10) NOT NULL default '0',

mysql-test/r/subselect.result

@@ -50,7 +50,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 Warnings:
 Note	1276	Field or reference 'a' of SELECT #3 was resolved in SELECT #1
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
-Note	1003	select 1 AS `1` from (select 1 AS `a`) `b` having ((select `b`.`a` AS `a`) = 1)
+Note	1003	select 1 AS `1` from (select 1 AS `a`) `b` having ((select '1' AS `a`) = 1)
 SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
 1
 1
@@ -204,7 +204,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 3	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Using filesort
 Warnings:
-Note	1003	select (select `test`.`t3`.`a` AS `a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
+Note	1003	select (select `test`.`t3`.`a` AS `a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,'2' AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2
@@ -315,7 +315,7 @@ NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL
 Warnings:
 Note	1276	Field or reference 'test.t2.a' of SELECT #2 was resolved in SELECT #1
 Note	1276	Field or reference 'test.t2.a' of SELECT #3 was resolved in SELECT #1
-Note	1003	select (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` = `test`.`t2`.`a`) union select `test`.`t5`.`a` AS `a` from `test`.`t5` where (`test`.`t5`.`a` = `test`.`t2`.`a`)) AS `(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)`,`test`.`t2`.`a` AS `a` from `test`.`t2`
+Note	1003	select (select '2' AS `a` from `test`.`t1` where ('2' = `test`.`t2`.`a`) union select `test`.`t5`.`a` AS `a` from `test`.`t5` where (`test`.`t5`.`a` = `test`.`t2`.`a`)) AS `(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)`,`test`.`t2`.`a` AS `a` from `test`.`t2`
 select (select a from t1 where t1.a=t2.a union all select a from t5 where t5.a=t2.a), a from t2;
 ERROR 21000: Subquery returns more than 1 row
 create table t6 (patient_uq int, clinic_uq int, index i1 (clinic_uq));
@@ -368,7 +368,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37		1	Using index
 Warnings:
-Note	1003	select `test`.`t8`.`pseudo` AS `pseudo`,(select `test`.`t8`.`email` AS `email` from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
+Note	1003	select 'joce' AS `pseudo`,(select 'test' AS `email` from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -547,7 +547,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	Using index
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 Warnings:
-Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = _latin1'1'))
+Note	1003	select '3' AS `numreponse` from `test`.`t1` where (('1' = _latin1'1'))
 drop table t1;
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);
@@ -1430,7 +1430,7 @@ explain extended (select * from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 Warnings:
-Note	1003	(select `test`.`t1`.`s1` AS `s1` from `test`.`t1`)
+Note	1003	(select 'tttt' AS `s1` from `test`.`t1`)
 (select * from t1);
 s1
 tttt
@@ -1497,7 +1497,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>((`test`.`t3`.`a` < (select max(`test`.`t2`.`b`) from `test`.`t2`)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>((`test`.`t3`.`a` < (select max('0') from `test`.`t2`)))
 select * from t3 where a >= some (select b from t2);
 a
 explain extended select * from t3 where a >= some (select b from t2);
@@ -1505,7 +1505,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>((`test`.`t3`.`a` >= (select min(`test`.`t2`.`b`) from `test`.`t2`)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>((`test`.`t3`.`a` >= (select min('0') from `test`.`t2`)))
 select * from t3 where a >= all (select b from t2 group by 1);
 a
 6
@@ -1516,7 +1516,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>((`test`.`t3`.`a` < <max>(select `test`.`t2`.`b` AS `b` from `test`.`t2` group by 1)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>((`test`.`t3`.`a` < <max>(select '0' AS `b` from `test`.`t2` group by 1)))
 select * from t3 where a >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where a >= some (select b from t2 group by 1);
@@ -1524,7 +1524,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>((`test`.`t3`.`a` >= <min>(select `test`.`t2`.`b` AS `b` from `test`.`t2` group by 1)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>((`test`.`t3`.`a` >= <min>(select '0' AS `b` from `test`.`t2` group by 1)))
 select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
@@ -1618,7 +1618,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 3	UNION	t1	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select `test`.`t1`.`s1` AS `s1` from `test`.`t1` where 1
+Note	1003	select 'e' AS `s1` from `test`.`t1` where 1
 drop table t1;
 CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
 INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');

mysql-test/r/union.result

@@ -480,7 +480,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	UNION	t2	const	PRIMARY	PRIMARY	4	const	1	
 NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	(select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where (`test`.`t1`.`a` = 1)) union (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` = 1))
+Note	1003	(select '1' AS `a`,'1' AS `b` from `test`.`t1` where ('1' = 1)) union (select '1' AS `a`,'10' AS `b` from `test`.`t2` where ('1' = 1))
 (select * from t1 where a=5) union (select * from t2 where a=1);
 a	b
 1	10

mysql-test/r/varbinary.result

@@ -15,7 +15,7 @@ explain extended select * from t1 where UNIQ=0x38afba1d73e6a18a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	const	UNIQ	UNIQ	8	const	1	
 Warnings:
-Note	1003	select `test`.`t1`.`ID` AS `ID`,`test`.`t1`.`UNIQ` AS `UNIQ` from `test`.`t1` where 1
+Note	1003	select '00000001' AS `ID`,'004084688022709641610' AS `UNIQ` from `test`.`t1` where 1
 drop table t1;
 select x'hello';
 ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'x'hello'' at line 1

sql/item.cc

@@ -1758,9 +1758,10 @@ void Item_ident::print(String *str)
     }
   }
 
-  if (!table_name || !field_name)
+  if (!table_name || !field_name || !field_name[0])
   {
-    const char *nm= field_name ? field_name : name ? name : "tmp_field";
+    const char *nm= (field_name && field_name[0]) ?
+                      field_name : name ? name : "tmp_field";
     append_identifier(thd, str, nm, (uint) strlen(nm));
     return;
   }
@@ -4900,6 +4901,22 @@ Item *Item_field::update_value_transformer(byte *select_arg)
 }
 
 
+void Item_field::print(String *str)
+{
+  if (field && field->table->const_table)
+  {
+    char buff[MAX_FIELD_WIDTH];
+    String tmp(buff,sizeof(buff),str->charset());
+    field->val_str(&tmp);
+    str->append('\'');
+    str->append(tmp);
+    str->append('\'');
+    return;
+  }
+  Item_ident::print(str);
+}
+
+
 Item_ref::Item_ref(Name_resolution_context *context_arg,
                    Item **item, const char *table_name_arg,
                    const char *field_name_arg,

sql/item.h

@@ -1303,6 +1303,7 @@ public:
   Item *safe_charset_converter(CHARSET_INFO *tocs);
   int fix_outer_field(THD *thd, Field **field, Item **reference);
   virtual Item *update_value_transformer(byte *select_arg);
+  void print(String *str);
   friend class Item_default_value;
   friend class Item_insert_value;
   friend class st_select_lex_unit;

sql/sql_union.cc

@@ -621,6 +621,12 @@ bool st_select_lex_unit::cleanup()
       join->tables= 0;
     }
     error|= fake_select_lex->cleanup();
+    if (fake_select_lex->order_list.elements)
+    {
+      ORDER *ord;
+      for (ord= (ORDER*)fake_select_lex->order_list.first; ord; ord= ord->next)
+        (*ord->item)->cleanup();
+    }
   }
 
   DBUG_RETURN(error);