[for-1.6] qemu-img: Error out for excess arguments

Don't silently ignore excess arguments at the end of the command line,
but error out instead. This can catch typos like 'resize test.img + 1G',
which doesn't increase the image size by 1G as intended, but truncates
the image to 1G. Even for less dangerous commands, the old behaviour is
confusing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-img.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

On 08/05/13 10:57, Kevin Wolf wrote:
> Don't silently ignore excess arguments at the end of the command line,
> but error out instead. This can catch typos like 'resize test.img + 1G',
> which doesn't increase the image size by 1G as intended, but truncates
> the image to 1G. Even for less dangerous commands, the old behaviour is
> confusing.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  qemu-img.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/qemu-img.c b/qemu-img.c
> index c55ca5c..dece1b3 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -396,6 +396,9 @@ static int img_create(int argc, char **argv)
>          }
>          img_size = (uint64_t)sval;
>      }
> +    if (optind != argc) {
> +        help();
> +    }
>  
>      if (options && is_help_option(options)) {
>          return print_block_option_help(filename, fmt);
> @@ -573,7 +576,7 @@ static int img_check(int argc, char **argv)
>              break;
>          }
>      }
> -    if (optind >= argc) {
> +    if (optind != argc - 1) {
>          help();
>      }
>      filename = argv[optind++];
> @@ -684,7 +687,7 @@ static int img_commit(int argc, char **argv)
>              break;
>          }
>      }
> -    if (optind >= argc) {
> +    if (optind != argc - 1) {
>          help();
>      }
>      filename = argv[optind++];
> @@ -930,7 +933,7 @@ static int img_compare(int argc, char **argv)
>      }
>  
>  
> -    if (optind > argc - 2) {
> +    if (optind != argc - 2) {
>          help();
>      }
>      filename1 = argv[optind++];
> @@ -1741,7 +1744,7 @@ static int img_info(int argc, char **argv)
>              break;
>          }
>      }
> -    if (optind >= argc) {
> +    if (optind != argc - 1) {
>          help();
>      }
>      filename = argv[optind++];
> @@ -1842,7 +1845,7 @@ static int img_snapshot(int argc, char **argv)
>          }
>      }
>  
> -    if (optind >= argc) {
> +    if (optind != argc - 1) {
>          help();
>      }
>      filename = argv[optind++];
> @@ -1953,7 +1956,7 @@ static int img_rebase(int argc, char **argv)
>          progress = 0;
>      }
>  
> -    if ((optind >= argc) || (!unsafe && !out_baseimg)) {
> +    if ((optind != argc - 1) || (!unsafe && !out_baseimg)) {
>          help();
>      }
>      filename = argv[optind++];
> @@ -2232,7 +2235,7 @@ static int img_resize(int argc, char **argv)
>              break;
>          }
>      }
> -    if (optind >= argc) {
> +    if (optind != argc - 1) {
>          help();
>      }
>      filename = argv[optind++];
> 

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

On Mon, Aug 05, 2013 at 10:57:40AM +0200, Kevin Wolf wrote:
> Don't silently ignore excess arguments at the end of the command line,
> but error out instead. This can catch typos like 'resize test.img + 1G',
> which doesn't increase the image size by 1G as intended, but truncates
> the image to 1G. Even for less dangerous commands, the old behaviour is
> confusing.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  qemu-img.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>