session-state dependent functions in DEFAULT/CHECK/vcols

* revert part of the db7edfe that moved calculations from
  fix_fields to val_str for Item_func_sysconst and descendants
* mark session state dependent functions in check_vcol_func_processor()
* re-run fix_fields for all such functions for every statement
* fix CURRENT_USER/CURRENT_ROLE not to use Name_resolution_context
  (that is allocated on the stack in unpack_vcol_info_from_frm())

Note that NOW(), CURDATE(), etc use lazy initialization and do *not*
force fix_fields to be re-run. The rule is:
* lazy initialization is *not* allowed, if it changes metadata (so,
   e.g. DAYNAME() cannot use it)
* lazy initialization is *preferrable* if it has side effects (e.g.
  NOW() sets thd->time_zone_used=1, so it's better to do it when
  the value of NOW is actually needed, not when NOW is simply prepared)

mysql-test/r/default.result

@@ -1084,33 +1084,6 @@ a	b
 20010101102030	2001
 DROP TABLE t1;
 #
-# Miscelaneous SQL standard <default option> variants
-#
-CREATE TABLE t1 (a VARCHAR(30) DEFAULT CURRENT_USER);
-ERROR HY000: Function or expression 'current_user()' cannot be used in the DEFAULT clause of `a`
-CREATE TABLE t1 (a VARCHAR(30) DEFAULT CURRENT_ROLE);
-ERROR HY000: Function or expression 'current_role()' cannot be used in the DEFAULT clause of `a`
-#
-# Other Item_func_sysconst derived functions
-#
-CREATE TABLE t1 (a VARCHAR(30) DEFAULT DATABASE());
-SHOW CREATE TABLE t1;
-Table	Create Table
-t1	CREATE TABLE `t1` (
-  `a` varchar(30) DEFAULT DATABASE()
-) ENGINE=MyISAM DEFAULT CHARSET=latin1
-INSERT INTO t1 VALUES ();
-USE INFORMATION_SCHEMA;
-INSERT INTO test.t1 VALUES ();
-USE test;
-INSERT INTO t1 VALUES ();
-SELECT * FROM t1;
-a
-test
-information_schema
-test
-DROP TABLE t1;
-#
 # Check DEFAULT() function
 #
 CREATE TABLE `t1` (`a` int(11) DEFAULT (3+3),`b` int(11) DEFAULT '1000');
@@ -1400,8 +1373,6 @@ SELECT * FROM t1;
 a	b	c
 01,5,2013	%d,%m,%Y	2013-05-01
 DROP TABLE t1;
-CREATE TABLE t1 (a VARCHAR(30), b VARCHAR(30) DEFAULT DATE_FORMAT(a,'%W %M %Y'));
-ERROR HY000: Function or expression 'date_format()' cannot be used in the DEFAULT clause of `b`
 # Item_datefunc
 SET time_zone='-10:00';
 SET timestamp=UNIX_TIMESTAMP('2001-01-01 23:59:59');
@@ -1835,10 +1806,6 @@ SELECT * FROM t1;
 a	b
 2008-04-01	2
 DROP TABLE t1;
-CREATE TABLE t1 (a DATE, b VARCHAR(30) DEFAULT DAYNAME(a));
-ERROR HY000: Function or expression 'dayname()' cannot be used in the DEFAULT clause of `b`
-CREATE TABLE t1 (a DATE, b VARCHAR(30) DEFAULT MONTHNAME(a));
-ERROR HY000: Function or expression 'monthname()' cannot be used in the DEFAULT clause of `b`
 CREATE TABLE t1 (a DATE, b INT DEFAULT EXTRACT(YEAR FROM a));
 SHOW CREATE TABLE t1;
 Table	Create Table

mysql-test/r/default_session.result

@@ -0,0 +1,94 @@
+create database mysqltest1;
+create user ''@localhost;
+create user foo@localhost;
+create role bar;
+grant select on *.* to ''@localhost;
+grant select,insert on *.* to foo@localhost;
+grant select,insert on *.* to bar;
+grant bar to ''@localhost;
+create table t1 (n varchar(100),
+u varchar(100) default user(),
+cu varchar(100) default current_user(),
+cr varchar(100) default current_role(),
+d  varchar(100) default database());
+create definer=foo@localhost view mysqltest1.v1 as select * from t1;
+create definer=bar           view            v2 as select * from t1;
+create                       view            v3 as select * from v2;
+create definer=foo@localhost view mysqltest1.v4 as select default(n),default(u),default(cu),default(cr), default(d) from t1;
+create definer=bar           view            v5 as select default(n),default(u),default(cu),default(cr), default(d) from t1;
+create                       view            v6 as select * from v5;
+insert t1 (n)  values ('t1');
+insert mysqltest1.v1 (n)  values ('v1');
+insert v2 (n)  values ('v2');
+insert v3 (n)  values ('v3');
+select default(n),default(u),default(cu),default(cr), default(d) from t1 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	root@localhost	root@localhost	NULL	test
+select * from mysqltest1.v4 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	root@localhost	foo@localhost	NULL	test
+select * from v5 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	root@localhost	@	bar	test
+select * from v6 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	root@localhost	@	bar	test
+connect  conn,localhost,conn,,mysqltest1;
+set role bar;
+insert test.t1 (n)  values ('t1');
+insert v1 (n)  values ('v1');
+insert test.v2 (n)  values ('v2');
+insert test.v3 (n)  values ('v3');
+select default(n),default(u),default(cu),default(cr), default(d) from test.t1 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	conn@localhost	@localhost	bar	mysqltest1
+select * from v4 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	conn@localhost	foo@localhost	NULL	mysqltest1
+select * from test.v5 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	conn@localhost	@	bar	mysqltest1
+select * from test.v6 limit 1;
+default(n)	default(u)	default(cu)	default(cr)	default(d)
+NULL	conn@localhost	@	bar	mysqltest1
+connection default;
+disconnect conn;
+select * from t1;
+n	u	cu	cr	d
+t1	root@localhost	root@localhost	NULL	test
+v1	root@localhost	foo@localhost	NULL	test
+v2	root@localhost	@	bar	test
+v3	root@localhost	@	bar	test
+t1	conn@localhost	@localhost	bar	mysqltest1
+v1	conn@localhost	foo@localhost	NULL	mysqltest1
+v2	conn@localhost	@	bar	mysqltest1
+v3	conn@localhost	@	bar	mysqltest1
+drop database mysqltest1;
+drop view v2, v3, v5, v6;
+drop table t1;
+drop user ''@localhost;
+drop user foo@localhost;
+drop role bar;
+create table t1 (a date,
+mn varchar(100) default monthname(a),
+dn varchar(100) default dayname(a),
+df varchar(100) default date_format(a, "%a, %b"));
+insert t1 (a) values ('2010-12-2');
+set lc_time_names=de_DE;
+insert t1 (a) values ('2010-12-2');
+set lc_time_names=default;
+select * from t1;
+a	mn	dn	df
+2010-12-02	December	Thursday	Thu, Dec
+2010-12-02	Dezember	Donnerstag	Do, Dez
+drop table t1;
+create table t1 (a varchar(100) default @@sql_mode);
+insert t1 () values ();
+set sql_mode=ansi;
+insert t1 () values ();
+set sql_mode=default;
+select * from t1;
+a
+NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI
+drop table t1;

mysql-test/suite/vcol/r/not_supported.result

@@ -14,12 +14,6 @@ create table t4 (a int, b int, v int as (@a:=a));
 ERROR HY000: Function or expression '@a' cannot be used in the GENERATED ALWAYS AS clause of `v`
 create table t4 (a int, b int, v int as (@a:=a) PERSISTENT);
 ERROR HY000: Function or expression '@a' cannot be used in the GENERATED ALWAYS AS clause of `v`
-create table t5 (a int, b int, v varchar(100) as (monthname(a)));
-ERROR HY000: Function or expression 'monthname()' cannot be used in the GENERATED ALWAYS AS clause of `v`
-create table t6 (a int, b int, v varchar(100) as (dayname(a)));
-ERROR HY000: Function or expression 'dayname()' cannot be used in the GENERATED ALWAYS AS clause of `v`
-create table t7 (a int, b int, v varchar(100) as (date_format(a, '%W %a %M %b')));
-ERROR HY000: Function or expression 'date_format()' cannot be used in the GENERATED ALWAYS AS clause of `v`
 create table t8 (a int, b int, v varchar(100) as (from_unixtime(a)));
 insert t1 (a,b) values (1,2);
 insert t8 (a,b) values (1234567890,2);

mysql-test/suite/vcol/r/vcol_blocked_sql_funcs.result

@@ -74,13 +74,6 @@ create or replace table t1 (a varchar(64), b varchar(64) as (collation(a)) PERSI
 create or replace table t1 (a int as (connection_id()));
 create or replace table t1 (a int as (connection_id()) PERSISTENT);
 ERROR HY000: Function or expression 'connection_id()' cannot be used in the GENERATED ALWAYS AS clause of `a`
-# CURRENT_USER(), CURRENT_USER
-create or replace table t1 (a varchar(32) as (current_user()));
-ERROR HY000: Function or expression 'current_user()' cannot be used in the GENERATED ALWAYS AS clause of `a`
-create or replace table t1 (a varchar(32) as (current_user()) PERSISTENT);
-ERROR HY000: Function or expression 'current_user()' cannot be used in the GENERATED ALWAYS AS clause of `a`
-create or replace table t1 (a varchar(32) as (current_user) PERSISTENT);
-ERROR HY000: Function or expression 'current_user()' cannot be used in the GENERATED ALWAYS AS clause of `a`
 # DATABASE()
 create or replace table t1 (a varchar(32) as (database()));
 create or replace table t1 (a varchar(1024), b varchar(1024) as (database()) PERSISTENT);
@@ -141,9 +134,6 @@ create or replace table t1 (a varchar(1024), b varchar(1024) as (version()) PERS
 ERROR HY000: Function or expression 'version()' cannot be used in the GENERATED ALWAYS AS clause of `b`
 # ENCRYPT()
 create or replace table t1 (a varchar(1024), b varchar(1024) as (encrypt(a)) PERSISTENT);
-# DATE_FORMAT()
-create or replace table t1 (a datetime, b varchar(64) as (date_format(a,'%W %M %D'));
-ERROR HY000: Function or expression 'date_format()' cannot be used in the GENERATED ALWAYS AS clause of `b`
 # Stored procedures
 create procedure p1()
 begin
@@ -217,15 +207,6 @@ ERROR HY000: Function or expression 'var_samp()' cannot be used in the GENERATED
 # VARIANCE()
 create or replace table t1 (a int, b int as (variance(a)));
 ERROR HY000: Function or expression 'variance()' cannot be used in the GENERATED ALWAYS AS clause of `b`
-# DAYNAME()
-create or replace table t1 (a int, b varchar(10) as (dayname(a)));
-ERROR HY000: Function or expression 'dayname()' cannot be used in the GENERATED ALWAYS AS clause of `b`
-create or replace table t1 (a int, b varchar(10) as (monthname(a)));
-ERROR HY000: Function or expression 'monthname()' cannot be used in the GENERATED ALWAYS AS clause of `b`
-create or replace table t1 (a int, b varchar(10) as (date_format("1963-01-01","%d.%m.%Y")));
-ERROR HY000: Function or expression 'date_format()' cannot be used in the GENERATED ALWAYS AS clause of `b`
-create or replace table t1 (a int, b varchar(10) as (time_format(now(),"%d.%m.%Y")));
-ERROR HY000: Function or expression 'time_format()' cannot be used in the GENERATED ALWAYS AS clause of `b`
 #
 # XML FUNCTIONS
 #

mysql-test/suite/vcol/r/vcol_supported_sql_funcs.result

@@ -2831,3 +2831,78 @@ a	b
 a	30
 drop table t1;
 set sql_warnings = 0;
+# MONTHNAME()
+set sql_warnings = 1;
+create table t1 (a date, b varchar(100) as (monthname(a)));
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` date DEFAULT NULL,
+  `b` varchar(100) AS (monthname(a)) VIRTUAL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t1 values ('2010-10-10',default);
+select * from t1;
+a	b
+2010-10-10	October
+drop table t1;
+set sql_warnings = 0;
+# DAYNAME()
+set sql_warnings = 1;
+create table t1 (a date, b varchar(100) as (dayname(a)));
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` date DEFAULT NULL,
+  `b` varchar(100) AS (dayname(a)) VIRTUAL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t1 values ('2011-11-11',default);
+select * from t1;
+a	b
+2011-11-11	Friday
+drop table t1;
+set sql_warnings = 0;
+# DATE_FORMAT()
+set sql_warnings = 1;
+create table t1 (a date, b varchar(100) as (date_format(a, '%W %a %M %b')));
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` date DEFAULT NULL,
+  `b` varchar(100) AS (date_format(a, '%W %a %M %b')) VIRTUAL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t1 values ('2012-12-12',default);
+select * from t1;
+a	b
+2012-12-12	Wednesday Wed December Dec
+drop table t1;
+set sql_warnings = 0;
+# CURRENT_USER()
+set sql_warnings = 1;
+create table t1 (a char, b varchar(32) as (current_user()));
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` char(1) DEFAULT NULL,
+  `b` varchar(32) AS (current_user()) VIRTUAL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t1 values ('a', default);
+select * from t1;
+a	b
+a	root@localhost
+drop table t1;
+set sql_warnings = 0;
+# TIME_FORMAT()
+set sql_warnings = 1;
+create table t1 (a datetime, b varchar(10) as (time_format(a,"%d.%m.%Y")));
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` datetime DEFAULT NULL,
+  `b` varchar(10) AS (time_format(a,"%d.%m.%Y")) VIRTUAL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t1 values ('2001-01-01 02:02:02',default);
+select * from t1;
+a	b
+2001-01-01 02:02:02	01.01.2001
+drop table t1;
+set sql_warnings = 0;

mysql-test/suite/vcol/t/not_supported.test

@@ -24,12 +24,6 @@ create table t3 (a int, b int, v int as (a+@@error_count) PERSISTENT);
 create table t4 (a int, b int, v int as (@a:=a));
 --error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
 create table t4 (a int, b int, v int as (@a:=a) PERSISTENT);
---error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create table t5 (a int, b int, v varchar(100) as (monthname(a)));
---error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create table t6 (a int, b int, v varchar(100) as (dayname(a)));
---error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create table t7 (a int, b int, v varchar(100) as (date_format(a, '%W %a %M %b')));
 create table t8 (a int, b int, v varchar(100) as (from_unixtime(a)));
 
 insert t1 (a,b) values (1,2);

mysql-test/suite/vcol/t/vcol_blocked_sql_funcs_main.inc

@@ -116,14 +116,6 @@ create or replace table t1 (a int as (connection_id()));
 -- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
 create or replace table t1 (a int as (connection_id()) PERSISTENT);
 
---echo # CURRENT_USER(), CURRENT_USER
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a varchar(32) as (current_user()));
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a varchar(32) as (current_user()) PERSISTENT);
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a varchar(32) as (current_user) PERSISTENT);
-
 --echo # DATABASE()
 create or replace table t1 (a varchar(32) as (database()));
 -- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
@@ -204,10 +196,6 @@ create or replace table t1 (a varchar(1024), b varchar(1024) as (version()) PERS
 --echo # ENCRYPT()
 create or replace table t1 (a varchar(1024), b varchar(1024) as (encrypt(a)) PERSISTENT);
 
---echo # DATE_FORMAT()
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a datetime, b varchar(64) as (date_format(a,'%W %M %D'));
-
 --echo # Stored procedures
 
 delimiter //;
@@ -308,19 +296,6 @@ create or replace table t1 (a int, b int as (var_samp(a)));
 -- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
 create or replace table t1 (a int, b int as (variance(a)));
 
---echo # DAYNAME()
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a int, b varchar(10) as (dayname(a)));
-
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a int, b varchar(10) as (monthname(a)));
-
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a int, b varchar(10) as (date_format("1963-01-01","%d.%m.%Y")));
-
--- error ER_VIRTUAL_COLUMN_FUNCTION_IS_NOT_ALLOWED
-create or replace table t1 (a int, b varchar(10) as (time_format(now(),"%d.%m.%Y")));
-
 --echo #
 --echo # XML FUNCTIONS
 --echo #

mysql-test/suite/vcol/t/vcol_supported_sql_funcs_main.inc

@@ -1179,3 +1179,33 @@ let $values1 = 'a',default;
 let $rows = 1;
 --source suite/vcol/inc/vcol_supported_sql_funcs.inc
 
+--echo # MONTHNAME()
+let $cols = a date, b varchar(100) as (monthname(a));
+let $values1 = '2010-10-10',default;
+let $rows = 1;
+--source suite/vcol/inc/vcol_supported_sql_funcs.inc
+
+--echo # DAYNAME()
+let $cols = a date, b varchar(100) as (dayname(a));
+let $values1 = '2011-11-11',default;
+let $rows = 1;
+--source suite/vcol/inc/vcol_supported_sql_funcs.inc
+
+--echo # DATE_FORMAT()
+let $cols = a date, b varchar(100) as (date_format(a, '%W %a %M %b'));
+let $values1 = '2012-12-12',default;
+let $rows = 1;
+--source suite/vcol/inc/vcol_supported_sql_funcs.inc
+
+--echo # CURRENT_USER()
+let $cols = a char, b varchar(32) as (current_user());
+let $values1 = 'a', default;
+let $rows = 1;
+--source suite/vcol/inc/vcol_supported_sql_funcs.inc
+
+--echo # TIME_FORMAT()
+let $cols = a datetime, b varchar(10) as (time_format(a,"%d.%m.%Y"));
+let $values1 = '2001-01-01 02:02:02',default;
+let $rows = 1;
+--source suite/vcol/inc/vcol_supported_sql_funcs.inc
+