Bug #75864 Incorrect handling of unsigned not null integers in innodb_memcached

Description:
Memcached plugin handles unsigned integer value columns incorrectly.

Column attributes are in several places compared to IB_COL_UNSIGNED:

    if (m_col->attr == IB_COL_UNSIGNED)

However, in case when there are any other flags (like IB_COL_NOT_NULL) set on the column this comparison fails.

How to repeat:
SQL commands to prepare a database:

USE innodb_memcache;

INSERT INTO containers VALUES ("int_test", "test", "int_test",
			       "k", "v",  "", "", "", "PRIMARY");

CREATE DATABASE IF NOT EXISTS test;
USE test

CREATE TABLE int_test (k varchar(32), v int unsigned NOT NULL, PRIMARY KEY (k)) ENGINE=InnoDB;

---

Inside a telnet connection to memcached:

get @@int_test
VALUE @@int_test 0 13
test/int_test
END

set somekey 0 0 3
543
STORED

get somekey
VALUE somekey 0 3
0
END

---

GET returns zero, despite being 543 (it can be checked using SQL).

Suggested fix:
Existence of IB_COL_UNSIGNED flag should be always determined by using binary & operator:

    if (m_col->attr & IB_COL_UNSIGNED)

Patch fixing this bug

(*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: unsigned.diff (text/plain), 3.09 KiB.

Hello Piotr Jurkiewicz,

Thank you for the report and contribution.

Thanks,
Umesh

// 5.6.24
// Build used, setup followed - http://dev.mysql.com/doc/refman/5.6/en/innodb-memcached-installing.html

commit: caae6b64ef613df007609b569b8368c599d5c995
date: 2015-02-03 12:05:54 +0100
build-date: 2015-02-03 18:45:47 +0100
short: caae6b6
branch: mysql-5.6

MySQL source 5.6.24

scripts/mysql_install_db --basedir=/export/umesh/mysql-5.6.24 --datadir=/export/umesh/mysql-5.6.24/75864
bin/mysqld --basedir=/export/umesh/mysql-5.6.24 --datadir=/export/umesh/mysql-5.6.24/75864 --core-file --socket=/tmp/mysql_ushastry.sock  --port=15000 --log-error=/export/umesh/mysql-5.6.24/75864/log.err 2>&1 &

//

[umshastr@hod03]/export/umesh/mysql-5.7.6: telnet localhost 11211
Trying ::1...
Connected to localhost.
Escape character is '^]'.
..

get @@int_test
VALUE @@int_test 0 13
test/int_test
END
set somekey 0 0 3
543
STORED
get somekey
VALUE somekey 0 5
32573
END

##  from CLI session

mysql> select * from int_test;
+---------+-----+
| k       | v   |
+---------+-----+
| somekey | 543 |
+---------+-----+
1 row in set (0.00 sec)

## uninstalled/installed memcached plugin to see if that helps

mysql> uninstall plugin daemon_memcached;
Query OK, 0 rows affected (2.00 sec)

mysql> install plugin daemon_memcached soname "libmemcached.so";
Query OK, 0 rows affected (0.00 sec)

//

[umshastr@hod03]~: telnet localhost 11211
Trying ::1...
Connected to localhost.
Escape character is '^]'.
get @@int_test
VALUE @@int_test 0 13
test/int_test
END
set somekey 0 0 3
543
STORED
get somekey
VALUE somekey 0 1
0
END

## from CLI session

mysql> select * from int_test;
+---------+-----+
| k       | v   |
+---------+-----+
| somekey | 543 |
+---------+-----+
1 row in set (0.00 sec)

Posted by developer:
 
Fixed as of the upcoming 5.6.26, 5.7.8, 5.8.0 releases, and here's the changelog entry:

The "InnoDB" "memcached" plugin handled unsigned NOT NULL integer columns
incorrectly. Thanks to Piotr Jurkiewicz for the patch. 

Thank you for the bug report.