Bug #37723 NAME_CONST() hangs forever, yet no query is running

Description:
A query with NAME_CONST appears to hang forever.  Another connection sees it as sleeping in the processlist.

How to repeat:
set @var := 0;
select actor_id, @var from sakila.actor where ((@var := @var + 1) <= name_const('foo', @var + 20)) and actor_id % 2 = 0 limit 20;

This hangs.

mysql> show full processlist\G
*************************** 1. row ***************************
     Id: 26
   User: baron
   Host: localhost
     db: NULL
Command: Query
   Time: 0
  State: NULL
   Info: show full processlist
*************************** 2. row ***************************
     Id: 27
   User: baron
   Host: localhost
     db: sakila
Command: Sleep
   Time: 167
  State: 
   Info: NULL
2 rows in set (0.00 sec)

Thank you for the problem report. Please, send the results of SHOW CREATE TABLE and SHOW TABLE STATUS for your sakila.actor table.

mysql> show create table actor\G
*************************** 1. row ***************************
       Table: actor
Create Table: CREATE TABLE `actor` (
  `actor_id` smallint(5) unsigned NOT NULL auto_increment,
  `first_name` varchar(45) NOT NULL,
  `last_name` varchar(45) NOT NULL,
  `last_update` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
  PRIMARY KEY  (`actor_id`),
  KEY `idx_actor_last_name` (`last_name`)
) ENGINE=InnoDB AUTO_INCREMENT=201 DEFAULT CHARSET=utf8
1 row in set (0.01 sec)

mysql> show table status like 'actor'\G
*************************** 1. row ***************************
           Name: actor
         Engine: InnoDB
        Version: 10
     Row_format: Compact
           Rows: 200
 Avg_row_length: 81
    Data_length: 16384
Max_data_length: 0
   Index_length: 16384
      Data_free: 0
 Auto_increment: 201
    Create_time: 2008-06-19 12:50:02
    Update_time: NULL
     Check_time: NULL
      Collation: utf8_general_ci
       Checksum: NULL
 Create_options: 
        Comment: InnoDB free: 8192 kB
1 row in set (0.00 sec)

Sorry, but I can not repeat the behaviour described with a newer version, 5.0.52:

C:\Program Files\MySQL\MySQL Server 5.0\bin>mysql -uroot -proot -P3308 test
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 5.0.62-enterprise-gpl-nt MySQL Enterprise Server (GPL)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> CREATE TABLE `actor` (
    ->   `actor_id` smallint(5) unsigned NOT NULL auto_increment,
    ->   `first_name` varchar(45) NOT NULL,
    ->   `last_name` varchar(45) NOT NULL,
    ->   `last_update` timestamp NOT NULL default CURRENT_TIMESTAMP on update CU
RRENT_TIMESTAMP,
    ->   PRIMARY KEY  (`actor_id`),
    ->   KEY `idx_actor_last_name` (`last_name`)
    -> ) ENGINE=InnoDB;
Query OK, 0 rows affected (0.17 sec)

mysql> insert into actor (first_name, last_name) values ('Bruce', 'Lee');
Query OK, 1 row affected (0.03 sec)

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 1 row affected (0.39 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 2 rows affected (0.03 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 4 rows affected (0.39 sec)
Records: 4  Duplicates: 0  Warnings: 0

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 8 rows affected (0.03 sec)
Records: 8  Duplicates: 0  Warnings: 0

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 16 rows affected (0.03 sec)
Records: 16  Duplicates: 0  Warnings: 0

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 32 rows affected (0.03 sec)
Records: 32  Duplicates: 0  Warnings: 0

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 64 rows affected (0.05 sec)
Records: 64  Duplicates: 0  Warnings: 0

mysql> insert into actor (first_name, last_name) select first_name, last_name fr
om actor;
Query OK, 128 rows affected (0.03 sec)
Records: 128  Duplicates: 0  Warnings: 0

mysql> set @var := 0;
Query OK, 0 rows affected (0.00 sec)

mysql> select actor_id, @var from sakila.actor where ((@var := @var + 1) <= name
_const('foo',
    -> @var + 20)) and actor_id % 2 = 0 limit 20;
ERROR 1210 (HY000): Incorrect arguments to NAME_CONST

Please, check if something is wrong in my test case.

Maybe it's arch-specific.  I'm on AMD64 Ubuntu.  I haven't tried the newer version.