Bug #1590 SET variable = NULL causes crash

• Submitted: 17 Oct 2003 15:11
• Modified: 19 Oct 2003 4:53
• Reporter: Peter Gulutzan
• Status: Can't repeat
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 4.1.1
• OS: Linux (SuSE 8.2)
• CPU Architecture: Any

[17 Oct 2003 15:11] Peter Gulutzan

Description:
For many of the variables described in the MySQL Reference Manual Section 5.5.6 SET 
Syntax (http://www.mysql.com/doc/en/SET_OPTION.html), assigning a NULL value causes 
a crash. Specific ones that I've tested are: 
set sql_auto_is_null = null; 
set autocommit = null; 
set sql_buffer_result = null; 
set low_priority_updates = null; 
set sql_log_bin = null; 
set sql_warnings = null; 
 
Monty Widenius is already aware that this happens with "set sql_warnings = null", so this 
notice appears as a matter of record only. 
 

How to repeat:
mysql> set autocommit = null; 
ERROR 2013 (HY000): Lost connection to MySQL server during query                                                               
mysql> 
 

Suggested fix:
Do not fix. Assume that Mr Widenius will look at it.

[19 Oct 2003 4:53] Oleksandr Byelkin

This bug fixed by Monty, patch: 
ChangeSet 1.1346.1.223 2003/10/14 16:30:42 [e-mail] 
  Fixed bug in SET enum_system_variable=NULL 
sql/set_var.cc 1.12.5.2 2003/10/14 16:30:39 [e-mail] 
  Fixed bug in SET enum_system_variable=NULL 
  Moved some array elements to get result sorted 
 
(I hope I assign correct state to this bug, because I can't close it, because 
I did not fix it (just tested and found why it work for now))