Merge linux-st28.site:/home/martin/mysql/src/bug32848/my50-bug32848-gca

into  linux-st28.site:/home/martin/mysql/src/bug32848/my51-bug32848-gca


mysql-test/r/union.result:
  Auto merged
mysql-test/t/union.test:
  Auto merged
sql/field.h:
  Auto merged
sql/sql_select.cc:
  Auto merged
sql/field.cc:
  Bug#32848: Manual merge
sql/item.cc:
  Bug#32848: Manual merge

mysql-test/r/bdb_notembedded.result

+set autocommit=1;
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+drop table bug16206;
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int) engine=         bdb
+f	n	Query	1	n	use `test`; insert into bug16206 values(0)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; BEGIN
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+f	n	Query	1	n	use `test`; COMMIT
+f	n	Query	1	n	use `test`; insert into bug16206 values(3)
+drop table bug16206;
+set autocommit=0;
+End of 5.0 tests

mysql-test/r/union.result

@@ -1445,4 +1445,28 @@ select @var;
 1
 (select 2) union (select 1 into @var);
 ERROR 42000: Result consisted of more than one row
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1), (2), (3);
+CREATE TABLE t2 SELECT * FROM (SELECT NULL) a UNION SELECT a FROM t1;
+DESC t2;
+Field	Type	Null	Key	Default	Extra
+NULL	int(11)	YES		NULL	
+CREATE TABLE t3 SELECT a FROM t1 UNION SELECT * FROM (SELECT NULL) a;
+DESC t3;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	YES		NULL	
+CREATE TABLE t4 SELECT NULL;
+DESC t4;
+Field	Type	Null	Key	Default	Extra
+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	
+CREATE TABLE t6 
+SELECT * FROM (SELECT * FROM (SELECT NULL)a) b UNION SELECT a FROM t1;
+DESC t6;
+Field	Type	Null	Key	Default	Extra
+NULL	int(11)	YES		NULL	
+DROP TABLE t1, t2, t3, t4, t5, t6;
 End of 5.0 tests

mysql-test/t/bdb_notembedded.test

+-- source include/not_embedded.inc
+-- source include/have_bdb.inc
+
+#
+# Bug #16206: Superfluous COMMIT event in binlog when updating BDB in autocommit mode
+#
+set autocommit=1;
+
+let $VERSION=`select version()`;
+
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+set autocommit=0;
+
+
+--echo End of 5.0 tests

mysql-test/t/union.test

@@ -922,4 +922,28 @@ DROP TABLE t1;
 select @var;
 --error 1172
 (select 2) union (select 1 into @var);
+
+#
+# Bug#32848: Data type conversion bug in union subselects in MySQL 5.0.38
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1), (2), (3);
+
+CREATE TABLE t2 SELECT * FROM (SELECT NULL) a UNION SELECT a FROM t1;
+DESC t2;
+
+CREATE TABLE t3 SELECT a FROM t1 UNION SELECT * FROM (SELECT NULL) a;
+DESC t3;
+
+CREATE TABLE t4 SELECT NULL;
+DESC t4;
+
+CREATE TABLE t5 SELECT NULL UNION SELECT NULL;
+DESC t5;
+
+CREATE TABLE t6 
+SELECT * FROM (SELECT * FROM (SELECT NULL)a) b UNION SELECT a FROM t1;
+DESC t6;
+
+DROP TABLE t1, t2, t3, t4, t5, t6;
 --echo End of 5.0 tests

sql/field.cc

@@ -1307,7 +1307,8 @@ Field::Field(uchar *ptr_arg,uint32 length_arg,uchar *null_ptr_arg,
    field_name(field_name_arg),
    key_start(0), part_of_key(0), part_of_key_not_clustered(0),
    part_of_sortkey(0), unireg_check(unireg_check_arg),
-   field_length(length_arg), null_bit(null_bit_arg)
+   field_length(length_arg), null_bit(null_bit_arg), 
+   is_created_from_null_item(FALSE)
 {
   flags=null_ptr ? 0: NOT_NULL_FLAG;
   comment.str= (char*) "";

sql/field.h

@@ -89,6 +89,16 @@ public:
   uint32	flags;
   uint16        field_index;            // field number in fields array
   uchar		null_bit;		// Bit used to test null bit
+  /**
+     If true, this field was created in create_tmp_field_from_item from a NULL
+     value. This means that the type of the field is just a guess, and the type
+     may be freely coerced to another type.
+
+     @see create_tmp_field_from_item
+     @see Item_type_holder::get_real_type
+
+   */
+  bool is_created_from_null_item;
 
   Field(uchar *ptr_arg,uint32 length_arg,uchar *null_ptr_arg,
         uchar null_bit_arg, utype unireg_check_arg,

sql/item.cc

@@ -6666,6 +6666,8 @@ enum_field_types Item_type_holder::get_real_type(Item *item)
     */
     Field *field= ((Item_field *) item)->field;
     enum_field_types type= field->real_type();
+    if (field->is_created_from_null_item)
+      return MYSQL_TYPE_NULL;
     /* work around about varchar type field detection */
     if (type == MYSQL_TYPE_STRING && field->type() == MYSQL_TYPE_VAR_STRING)
       return MYSQL_TYPE_VAR_STRING;
@@ -6924,6 +6926,8 @@ Field *Item_type_holder::make_field_by_type(TABLE *table)
     if (field)
       field->init(table);
     return field;
+  case MYSQL_TYPE_NULL:
+    return make_string_field(table);
   default:
     break;
   }

sql/sql_select.cc

@@ -9202,6 +9202,8 @@ static Field *create_tmp_field_from_item(THD *thd, Item *item, TABLE *table,
     *((*copy_func)++) = item;			// Save for copy_funcs
   if (modify_item)
     item->set_result_field(new_field);
+  if (item->type() == Item::NULL_ITEM)
+    new_field->is_created_from_null_item= TRUE;
   return new_field;
 }