Bug #46314 string system variables don't support expressions
Submitted: 20 Jul 2009 16:26 Modified: 16 Mar 2010 0:07
Reporter: Sergei Golubchik Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Options Severity:S3 (Non-critical)
Version:any OS:Any
Assigned to: CPU Architecture:Any

[20 Jul 2009 16:26] Sergei Golubchik 
Description:
System variables that store a string value take it directly from Item::str_value, which only works for string literals. They should call val_str() instead.

NUmeric variables call val_int() as expected.

How to repeat:
set global ft_boolean_syntax=concat('a','b');

for comparison, try

set global ft_boolean_syntax='ab';
set global max_prepared_stmt_count=1+1; select @@max_prepared_stmt_count;
[20 Jul 2009 16:59] MySQL Verification Team 
Thank you for the bug report.
[31 Aug 2009 17:04] Sergei Golubchik 
will be fixed in WL#4738
[6 Mar 2010 10:55] Bugs System 
Pushed into 5.5.3-m3 (revid:alik@sun.com-20100306103849-hha31z2enhh7jwt3) (version source revid:vvaintroub@fedora12-20091225154921-x25a5pyw1pxiwobv) (merge vers: 5.5.99) (pib:16)
[16 Mar 2010 0:07] Paul DuBois 
Noted in 5.5.3 changelog.

String-valued system variables could be assigned literal values, but
could not be assigned values using expressions. Now expressions are
legal.