Commit f8bf427b authored by gshchepa/uchum@gleb.loc's avatar gshchepa/uchum@gleb.loc
Browse files

Fixed bug #29251. 

Sometimes special 0 ENUM values was ALTERed to normal
empty string ENUM values.

Special 0 ENUM value has the same string representation
as normal ENUM value defined as '' (empty string).
The do_field_string function was used to convert
ENUM data at an ALTER TABLE request, but this
function doesn't care about numerical "indices" of
ENUM values, i.e. do_field_string doesn't distinguish
a special 0 value from an empty string value.

A new copy function called do_field_enum has been added to
copy special 0 ENUM values without conversion to an empty
string.
parent 78e900dd

mysql-test/r/type_enum.result

+23 −0
Original line number Diff line number Diff line
@@ -1778,4 +1778,27 @@ drop table t1; 
create table t1(exhausting_charset enum('ABCDEFGHIJKLMNOPQRSTUVWXYZ','	


 !"','#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~','xx\','yy\','zz'));

ERROR 42000: Field separator argument is not what is expected; check the manual

CREATE TABLE t1 (

id INT AUTO_INCREMENT PRIMARY KEY,

c1 ENUM('a', '', 'b')

);

INSERT INTO t1 (c1) VALUES (0), ('a'), (''), ('b');

Warnings:

Warning	1265	Data truncated for column 'c1' at row 1

SELECT id, c1 + 0, c1 FROM t1;

id	c1 + 0	c1

1	0	

2	1	a

3	2	

4	3	b

ALTER TABLE t1 CHANGE c1 c1 ENUM('a', '') NOT NULL;

Warnings:

Warning	1265	Data truncated for column 'c1' at row 4

SELECT id, c1 + 0, c1 FROM t1;

id	c1 + 0	c1

1	0	

2	1	a

3	2	

4	0	

DROP TABLE t1;

End of 4.1 tests

mysql-test/t/type_enum.test

+17 −0
Original line number Diff line number Diff line
@@ -156,4 +156,21 @@ drop table t1; 
create table t1(exhausting_charset enum('ABCDEFGHIJKLMNOPQRSTUVWXYZ','	


 !"','#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~','xx\','yy\','zz'));



#

# Bug #29251: MySQL coerces special 0 enum values to normal '' value

# when ALTERing the column

#



CREATE TABLE t1 (

  id INT AUTO_INCREMENT PRIMARY KEY,

  c1 ENUM('a', '', 'b')

);

INSERT INTO t1 (c1) VALUES (0), ('a'), (''), ('b');

SELECT id, c1 + 0, c1 FROM t1;



ALTER TABLE t1 CHANGE c1 c1 ENUM('a', '') NOT NULL;

SELECT id, c1 + 0, c1 FROM t1;



DROP TABLE t1;



--echo End of 4.1 tests

sql/field_conv.cc

+16 −1
Original line number Diff line number Diff line
@@ -311,6 +311,15 @@ static void do_field_string(Copy_field *copy) 
}





static void do_field_enum(Copy_field *copy)

{

  if (copy->from_field->val_int() == 0)

    ((Field_enum *) copy->to_field)->store_type((ulonglong) 0);

  else

    do_field_string(copy);

}





static void do_field_int(Copy_field *copy)

{

  longlong value=copy->from_field->val_int();
@@ -538,8 +547,14 @@ void (*Copy_field::get_copy_func(Field *to,Field *from))(Copy_field*) 
	  to->real_type() == FIELD_TYPE_SET)

      {

	if (!to->eq_def(from))

        {

          if (from->real_type() == MYSQL_TYPE_ENUM &&

              to->real_type() == MYSQL_TYPE_ENUM)

            return do_field_enum;

          else

            return do_field_string;

        }

      }

      else if (to->charset() != from->charset())

	return do_field_string;

      else if (to->real_type() == FIELD_TYPE_VAR_STRING && to_length !=