    public static function mb_substitute_character($c = null)
    {
        if (0 === strcasecmp($c, 'none')) {
            return true;
        }

        return null !== $c ? false : 'none';
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.