Re: variable hooks & global variables

[Robert Millan]

On Sat, Jan 05, 2008 at 02:22:17AM +0100, Yoshinori K. Okuji wrote:
> On Thursday 03 January 2008 16:05, Robert Millan wrote:
> > On Thu, Jan 03, 2008 at 04:03:11PM +0100, Robert Millan wrote:
> > > When you set a variable hook (grub_register_variable_hook), this hook
> > > isn't preserved after someone (e.g. configfile command) opens a new
> > > context (grub_env_context_open), unless the variable has been set as
> > > global (grub_env_export).
> > >
> > > Is this what we want?
> > >
> > > The only current user of variable hooks is "root" variable, and that hook
> > > contains a sanity check that seems to be more suitable for global scope.
> > >
> > > The color-related variables for which I wanted to add hooks would also
> > > like to keep their hooks across contexts.
> > >
> > > One option is to export these variables, or to modify
> > > grub_env_context_open() to preserve hooks as well as exported variables. 
> > > I'm more inclined for the latter.
> > >
> > > Comments?
> >
> > Erm, ignore the part about global variables.  Exporting them doesn't help:
> >
> >       for (var = context->prev->vars[i]; var; var = var->next)
> >         {
> >           if (var->type == GRUB_ENV_VAR_GLOBAL)
> >             if (grub_env_set (var->name, var->value) != GRUB_ERR_NONE)
> >               {
> >                 grub_env_context_close ();
> >                 return grub_errno;
> >               }
> >         }
> >
> > So, we just preserve hooks ?
> 
> Global variables should preserve hooks. This is a bug.

Fixed then.

> Local ones should not. 
> If you want to have a variable to be inherited, you must make it global.

Ok.

-- 
Robert Millan

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<DRM> What use is a phone call, if you are unable to speak?
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