Re: [Qemu-devel] [PATCH 06/15] qga: Use return values instead of error_is_set(errp)

[Luiz Capitulino]

On Fri, 25 Apr 2014 12:21:22 -0600
Eric Blake <address@hidden> wrote:

> On 04/25/2014 12:06 PM, Markus Armbruster wrote:
> > Eric Blake <address@hidden> writes:
> > 
> >> On 04/25/2014 09:05 AM, Markus Armbruster wrote:
> >>> Using error_is_set(errp) to check whether a function call failed is
> >>> fragile: it breaks when errp is null.  I'm not aware of actual
> >>> breakage, but checking return values instead when convenient is more
> >>> robust and more obviously correct.
> >>>
> 
> >>>      handle = ga_get_fd_handle(ga_state, errp);
> >>> -    if (error_is_set(errp)) {
> >>> -        return 0;
> >>> +    if (handle < 0) {
> >>> +        return -1;
> >>
> >> Is this a bug fix that should be pushed separately, or at least called
> >> out in the commit message as intentional?
> > 
> > The return value is only used when no error has been set.  So, it's at
> > worst a latent bug.
> > 
> 
> > 
> > What about adding the following to the commit message:
> > 
> >     qga: Use return values instead of error_is_set(errp)
> > 
> >     Using error_is_set(errp) to check whether a function call failed is
> >     fragile: it breaks when errp is null.  ga_get_fd_handle() and
> >     guest_file_handle_add() don't return a useful value when they fail,
> >     but that's just stupid.  Fix that, and check them instead.  As far
> >     as I can tell, errp can't be null there, but this is more robust and
> >     more obviously correct.
> 
> Works for me.  I didn't spot anything else odd, so:
> 
> Series: Reviewed-by: Eric Blake <address@hidden>

Sorry to ask you something silly, but could you do that to the intro
email so that I don't miss it next week?