Bug #34883 ft_boolean_syntax cant be assigned from user variable to global var.

• Submitted: 27 Feb 2008 11:14
• Modified: 16 Mar 2010 0:07
• Reporter: Salman Rawala
• Status: Closed
• Category: MySQL Server: DML
• Severity: S3 (Non-critical)
• Version: 5.1.23
• OS: Any
• CPU Architecture: Any
• Tags: ft_boolean_syntax

[27 Feb 2008 11:14] Salman Rawala

Description:
When you finally assign temporary initial variable's value to session value, an error occurs that '' value cannot be set to variable

How to repeat:
Sample Code: 
SELECT @global_start_value;
--Error ER_WRONG_VALUE_FOR_VAR
SET @@global.ft_boolean_syntax = @global_start_value;

Actual Result: 
SELECT @global_start_value;
@global_start_value
+ -><()~*:""&|
SET @@global.ft_boolean_syntax = @global_start_value;
ERROR 42000: Variable 'ft_boolean_syntax' can't be set to the value of ''

[27 Feb 2008 11:28] Valeriy Kravchuk

Thank you for a bug report. Other variables, e.g. @@global.key_buffer_size, can be set this way, so it looks like inconsistency.

[27 Feb 2008 15:23] Sergei Golubchik

The manual specifies what values are allowed for ft_boolean_syntax. Empty string is not one of them.

And this has nothing to do with temporary variables.

[12 Mar 2008 11:33] Salman Rawala

So it means that we can not assign temporary variable to ft_boolean_syntax even if the variable contains the valid value.

SET @global_start_value = @@global.ft_boolean_syntax;
SELECT @global_start_value;
@global_start_value
+ -><()~*:""&|
SET @@global.ft_boolean_syntax = @global_start_value;
ERROR 42000: Variable 'ft_boolean_syntax' can't be set to the value of ''

As we can see that @global_start_value contains valid value but assigning this  variable is causing the problem.

[13 Mar 2008 10:46] Sergei Golubchik

You're right, sorry for confusion.

Hint: the code uses var->value->str_value.c_ptr(), it should use var->value->val_str() for an obvious reason. this was copy-pasted all over set_var.cc, all places should be fixed.

[13 Mar 2008 21:05] Omer Barnir

workaround: set the value of the via program code

[10 Aug 2009 10:45] Sergei Golubchik

will be fixed in WL#4738

[6 Mar 2010 11:08] Bugs System

Pushed into 5.5.3-m3 (revid:[e-mail]-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.