Merge bk-internal.mysql.com:/home/bk/mysql-4.1

into mysql.com:/home/dlenev/src/mysql-4.1-ryan

mysql-test/r/type_timestamp.result

@@ -369,7 +369,7 @@ create table t1 (a timestamp null, b timestamp null);
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `a` timestamp NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
+  `a` timestamp NULL default NULL,
   `b` timestamp NULL default NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 insert into t1 values (NULL, NULL);
@@ -378,7 +378,22 @@ insert into t1 values ();
 select * from t1;
 a	b
 NULL	NULL
-2001-09-09 04:46:57	NULL
+NULL	NULL
+drop table t1;
+create table t1 (a timestamp null default current_timestamp on update current_timestamp, b timestamp null);
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` timestamp NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
+  `b` timestamp NULL default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t1 values (NULL, NULL);
+SET TIMESTAMP=1000000018;
+insert into t1 values ();
+select * from t1;
+a	b
+NULL	NULL
+2001-09-09 04:46:58	NULL
 drop table t1;
 create table t1 (a timestamp null default null, b timestamp null default '2003-01-01 00:00:00');
 show create table t1;

mysql-test/t/type_timestamp.test

@@ -236,9 +236,10 @@ drop table t1;
 
 #
 # Test for TIMESTAMP columns which are able to store NULLs
-# (Auto-set property should work for them and NULL values
-#  should be OK as default values)
 #
+
+# Unlike for default TIMESTAMP fields we don't interpret first field
+# in this table as TIMESTAMP with DEFAULT NOW() ON UPDATE NOW() properties.
 create table t1 (a timestamp null, b timestamp null);
 show create table t1;
 insert into t1 values (NULL, NULL);
@@ -247,6 +248,16 @@ insert into t1 values ();
 select * from t1;
 drop table t1;
 
+# But explicit auto-set properties still should be OK.
+create table t1 (a timestamp null default current_timestamp on update current_timestamp, b timestamp null);
+show create table t1;
+insert into t1 values (NULL, NULL);
+SET TIMESTAMP=1000000018;
+insert into t1 values ();
+select * from t1;
+drop table t1;
+
+# It is also OK to specify NULL as default explicitly for such fields.
 create table t1 (a timestamp null default null, b timestamp null default '2003-01-01 00:00:00');
 show create table t1;
 insert into t1 values (NULL, NULL);

sql/sql_parse.cc

@@ -4142,11 +4142,6 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
     }
     else if (default_value->type() == Item::NULL_ITEM)
     {
-      /*
-        TIMESTAMP type should be able to distingush non-specified default
-        value and default value NULL later.
-      */
-      if (type != FIELD_TYPE_TIMESTAMP)
       default_value= 0;
       if ((type_modifier & (NOT_NULL_FLAG | AUTO_INCREMENT_FLAG)) ==
 	  NOT_NULL_FLAG)
@@ -4357,19 +4352,27 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
       else
         new_field->unireg_check= (on_update_value?Field::TIMESTAMP_UN_FIELD:
                                                   Field::NONE);
-
-      if (default_value->type() == Item::NULL_ITEM)
-        new_field->def= 0;
     }
     else
     {
       /*
-        We are setting TIMESTAMP_OLD_FIELD here only temporary, we will 
+        If we have default TIMESTAMP NOT NULL column without explicit DEFAULT
+        or ON UPDATE values then for the sake of compatiblity we should treat
+        this column as having DEFAULT NOW() ON UPDATE NOW() (when we don't
+        have another TIMESTAMP column with auto-set option before this one)
+        or DEFAULT 0 (in other cases).
+        So here we are setting TIMESTAMP_OLD_FIELD only temporary, and will
         replace this value by TIMESTAMP_DNUN_FIELD or NONE later when
         information about all TIMESTAMP fields in table will be availiable.
+
+        If we have TIMESTAMP NULL column without explicit DEFAULT value
+        we treat it as having DEFAULT NULL attribute.
       */
-      new_field->unireg_check= on_update_value?Field::TIMESTAMP_UN_FIELD:
-                                               Field::TIMESTAMP_OLD_FIELD;
+      new_field->unireg_check= on_update_value ?
+                               Field::TIMESTAMP_UN_FIELD :
+                               (new_field->flags & NOT_NULL_FLAG ?
+                                Field::TIMESTAMP_OLD_FIELD:
+                                Field::NONE);
     }
     break;
   case FIELD_TYPE_DATE:				// Old date type