Re: [Qemu-devel] [PATCH V3 01/11] qemu-img: remove unused parameter in collect_image_info()

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue, 15 Jan 2013 15:58:34 +0800
Wenchao Xia <xiawenc@linux.vnet.ibm.com> wrote:

> 于 2013-1-15 15:27, Wenchao Xia 写道:
> > 于 2013-1-15 1:08, Luiz Capitulino 写道:
> >> On Mon, 14 Jan 2013 15:09:37 +0800
> >> Wenchao Xia <xiawenc@linux.vnet.ibm.com> wrote:
> >>
> >>>    Parameter *fmt was not used, so remove it.
> >>>
> >>> Reviewed-by: Eric Blake <eblake@redhat.com>
> >>> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
> >>> ---
> >>>   qemu-img.c |    5 ++---
> >>>   1 files changed, 2 insertions(+), 3 deletions(-)
> >>>
> >>> diff --git a/qemu-img.c b/qemu-img.c
> >>> index 85d3740..9dab48f 100644
> >>> --- a/qemu-img.c
> >>> +++ b/qemu-img.c
> >>> @@ -1186,8 +1186,7 @@ static void dump_json_image_info(ImageInfo *info)
> >>>
> >>>   static void collect_image_info(BlockDriverState *bs,
> >>>                      ImageInfo *info,
> >>> -                   const char *filename,
> >>> -                   const char *fmt)
> >>> +                   const char *filename)
> >>
> >> collect_image_info_list() doc reads:
> >>
> >>   @fmt: topmost image format (may be NULL to autodetect)
> >>
> >> However, right now only fmt=NULL is supported, as collect_image_info()
> >> ignores fmt altogether.
> >>
> >> So, if this patch is correct we better update the comment. Otherwise,
> >> we should improve collect_image_info() to actually obey fmt != NULL.
> >>
> >    @fmt was ignored in the function and I can't see a reason to have
> > it while *bs contains the info, will change the comments.
> >
>    Hi, *fmt was used only in collect_image_info_list() when it tries to
> open the image, and it is not useful any more in collect_image_info,
> so nothing need change in comments.

This really doesn't answer my comment above. The code comment implies that
fmt may be NULL or non-NULL and they have different behavior.

If you choose to touch fmt (as this patch does) then please, do the
right thing. Otherwise it's better to let it untouched.