Fix for bug #22377: iNCONSISTENCY WITH null

Backport. See #20910: NOT NULL column reported as NULL in SHOW FIELDS or INFORMATION_SCHEMA

mysql-test/r/type_ranges.result

@@ -54,7 +54,7 @@ ushort	smallint(5) unsigned zerofill	NULL		MUL	00000		#
 umedium	mediumint(8) unsigned	NULL		MUL	0		#	
 ulong	int(11) unsigned	NULL		MUL	0		#	
 ulonglong	bigint(13) unsigned	NULL		MUL	0		#	
-time_stamp	timestamp	NULL	YES		CURRENT_TIMESTAMP		#	
+time_stamp	timestamp	NULL			CURRENT_TIMESTAMP		#	
 date_field	date	NULL	YES		NULL		#	
 time_field	time	NULL	YES		NULL		#	
 date_time	datetime	NULL	YES		NULL		#	
@@ -222,7 +222,7 @@ ushort	smallint(5) unsigned zerofill	NULL			00000		#
 umedium	mediumint(8) unsigned	NULL		MUL	0		#	
 ulong	int(11) unsigned	NULL		MUL	0		#	
 ulonglong	bigint(13) unsigned	NULL		MUL	0		#	
-time_stamp	timestamp	NULL	YES		CURRENT_TIMESTAMP		#	
+time_stamp	timestamp	NULL			CURRENT_TIMESTAMP		#	
 date_field	varchar(10)	latin1_swedish_ci	YES		NULL		#	
 time_field	time	NULL	YES		NULL		#	
 date_time	datetime	NULL	YES		NULL		#	
@@ -248,7 +248,7 @@ ushort	smallint(5) unsigned zerofill	NULL			00000		#
 umedium	mediumint(8) unsigned	NULL			0		#	
 ulong	int(11) unsigned	NULL			0		#	
 ulonglong	bigint(13) unsigned	NULL			0		#	
-time_stamp	timestamp	NULL	YES		0000-00-00 00:00:00		#	
+time_stamp	timestamp	NULL			0000-00-00 00:00:00		#	
 date_field	varchar(10)	latin1_swedish_ci	YES		NULL		#	
 time_field	time	NULL	YES		NULL		#	
 date_time	datetime	NULL	YES		NULL		#	

mysql-test/r/type_timestamp.result

@@ -188,9 +188,9 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 show columns from t1;
 Field	Type	Null	Key	Default	Extra
-t1	timestamp	YES		2003-01-01 00:00:00	
+t1	timestamp			2003-01-01 00:00:00	
 t2	datetime	YES		NULL	
-t3	timestamp	YES		0000-00-00 00:00:00	
+t3	timestamp			0000-00-00 00:00:00	
 drop table t1;
 create table t1 (t1 timestamp default now(), t2 datetime, t3 timestamp);
 SET TIMESTAMP=1000000002;
@@ -212,9 +212,9 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 show columns from t1;
 Field	Type	Null	Key	Default	Extra
-t1	timestamp	YES		CURRENT_TIMESTAMP	
+t1	timestamp			CURRENT_TIMESTAMP	
 t2	datetime	YES		NULL	
-t3	timestamp	YES		0000-00-00 00:00:00	
+t3	timestamp			0000-00-00 00:00:00	
 drop table t1;
 create table t1 (t1 timestamp default '2003-01-01 00:00:00' on update now(), t2 datetime);
 SET TIMESTAMP=1000000004;
@@ -238,7 +238,7 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 show columns from t1;
 Field	Type	Null	Key	Default	Extra
-t1	timestamp	YES		2003-01-01 00:00:00	
+t1	timestamp			2003-01-01 00:00:00	
 t2	datetime	YES		NULL	
 drop table t1;
 create table t1 (t1 timestamp default now() on update now(), t2 datetime);
@@ -263,7 +263,7 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 show columns from t1;
 Field	Type	Null	Key	Default	Extra
-t1	timestamp	YES		CURRENT_TIMESTAMP	
+t1	timestamp			CURRENT_TIMESTAMP	
 t2	datetime	YES		NULL	
 drop table t1;
 create table t1 (t1 timestamp, t2 datetime, t3 timestamp);
@@ -289,9 +289,9 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 show columns from t1;
 Field	Type	Null	Key	Default	Extra
-t1	timestamp	YES		CURRENT_TIMESTAMP	
+t1	timestamp			CURRENT_TIMESTAMP	
 t2	datetime	YES		NULL	
-t3	timestamp	YES		0000-00-00 00:00:00	
+t3	timestamp			0000-00-00 00:00:00	
 drop table t1;
 create table t1 (t1 timestamp default current_timestamp on update current_timestamp, t2 datetime);
 SET TIMESTAMP=1000000009;
@@ -315,7 +315,7 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 show columns from t1;
 Field	Type	Null	Key	Default	Extra
-t1	timestamp	YES		CURRENT_TIMESTAMP	
+t1	timestamp			CURRENT_TIMESTAMP	
 t2	datetime	YES		NULL	
 delete from t1;
 insert into t1 values ('2004-04-01 00:00:00', '2004-04-01 00:00:00');

sql/sql_show.cc

@@ -714,16 +714,7 @@ mysqld_show_fields(THD *thd, TABLE_LIST *table_list,const char *wild,
 	if (verbose)
 	  protocol->store(field->has_charset() ? field->charset()->name : "NULL",
 			system_charset_info);
-        /*
-          Even if TIMESTAMP field can't contain NULL as its value it
-          will accept NULL if you will try to insert such value and will
-          convert NULL value to current TIMESTAMP. So YES here means
-          that NULL is allowed for assignment (but may be won't be
-          returned).
-        */
-        pos=(byte*) ((flags & NOT_NULL_FLAG) &&
-                     field->type() != FIELD_TYPE_TIMESTAMP ?
-                     "" : "YES");
+        pos= (byte*) ((flags & NOT_NULL_FLAG) ? "" : "YES");
         protocol->store((const char*) pos, system_charset_info);
         pos=(byte*) ((field->flags & PRI_KEY_FLAG) ? "PRI" :
                      (field->flags & UNIQUE_KEY_FLAG) ? "UNI" :