On Mon, Dec 07, 2015 at 08:55:10PM -0700, Eric Blake wrote:
> Now that the QMP output visitor supports an explicit null
> output, we should utilize it to make it easier to diagnose
> the difference between a missing fdt vs. a present-but-empty
> one.
> 
> (Note that this reverts the behavior of commit ab8bf1d, taking
> us back to the behavior of commit 1d10b44; but that this time,
> the change is intentional and not an accidental side-effect.)
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> Cc: David Gibson <david@gibson.dropbear.id.au>

Acked-by: David Gibson <david@gibson.dropbear.id.au>

> 
> ---
> v7: new patch, based on discussion about spapr_drc.c
> ---
>  hw/ppc/spapr_drc.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> index dcce563..0c675ff 100644
> --- a/hw/ppc/spapr_drc.c
> +++ b/hw/ppc/spapr_drc.c
> @@ -259,11 +259,7 @@ static void prop_get_fdt(Object *obj, Visitor *v, void *opaque,
>      void *fdt;
> 
>      if (!drc->fdt) {
> -        visit_start_struct(v, NULL, 0, name, &err);
> -        if (!err) {
> -            visit_end_struct(v, &err);
> -        }
> -        error_propagate(errp, err);
> +        visit_type_null(v, NULL, errp);
>          return;
>      }
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson