MySQL Bugs: #38889: Assignment of a variable to "slow_query_log

Bug #38889	Assignment of a variable to "slow_query_log_file" failed.
Submitted:	19 Aug 2008 11:14	Modified:	4 Dec 2008 11:07
Reporter:	Horst Hunger	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	MySQL Server: Logging	Severity:	S3 (Non-critical)
Version:	6.0.7-alpha-debug	OS:	Linux (suse-linux-gnu on i686)
Assigned to:	Georgi Kodinov	CPU Architecture:	Any
Triage:	Triaged: D4 (Minor)

Description:
After execution of 
SET @my_var= "mytestvar.log";
SET @@global.slow_query_log_file= @my_var;
SELECT @@global.slow_query_log_file;

the result of the last select is  "/work/bzr/mysql-6.0-rpl/mysql-test/var/run/mysqld-slow.log" and not
"mytestvar.log".

How to repeat:
execute the attached test.

Suggested fix:
Either reject the assignment with a bug and describe the restriction in the manual or do the assignment as expected.

Thank you for the bug report.

Other variables can be set this way:

C:\Program Files\MySQL\MySQL Server 5.1\bin>mysql -uroot -P3311 test
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 6.0.5-alpha-community MySQL Community Server (GPL)

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

mysql> set @var=300000;
Query OK, 0 rows affected (0.00 sec)

mysql> set @@global.sort_buffer_size=@var;
Query OK, 0 rows affected (0.03 sec)

mysql> show global variables like 'sort%';
+------------------+--------+
| Variable_name    | Value  |
+------------------+--------+
| sort_buffer_size | 300000 |
+------------------+--------+
1 row in set (0.20 sec)

Duplicate of Bug#38124