[Libguestfs] [libnbd PATCH 2/2] api: Test previous patch

[Laszlo Ersek]

On 08/24/22 04:53, Eric Blake wrote:
> Add testsuite coverage that exposes the flaw fixed in the previous patch.
> 
> ---
>  tests/opt-info.c | 20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/tests/opt-info.c b/tests/opt-info.c
> index b9739a5..2402a31 100644
> --- a/tests/opt-info.c
> +++ b/tests/opt-info.c
> @@ -1,5 +1,5 @@
>  /* NBD client library in userspace
> - * Copyright (C) 2013-2020 Red Hat Inc.
> + * Copyright (C) 2013-2022 Red Hat Inc.
>   *
>   * This library is free software; you can redistribute it and/or
>   * modify it under the terms of the GNU Lesser General Public
> @@ -80,15 +80,11 @@ main (int argc, char *argv[])
>      exit (EXIT_FAILURE);
>    }
> 
> -  /* info on something not present fails, wipes out prior info */
> +  /* changing export wipes out prior info */
>    if (nbd_set_export_name (nbd, "a") == -1) {
>      fprintf (stderr, "%s\n", nbd_get_error ());
>      exit (EXIT_FAILURE);
>    }
> -  if (nbd_opt_info (nbd) != -1) {
> -    fprintf (stderr, "expecting error for opt_info\n");
> -    exit (EXIT_FAILURE);
> -  }
>    if (nbd_get_size (nbd) != -1) {
>      fprintf (stderr, "expecting error for get_size\n");
>      exit (EXIT_FAILURE);

Is this well targeted though?

Here we can't say whether nbd_get_size() fails because export "a" is
different from the previous "" export, or because "a" does not exist. If
"a" existed and nbd_get_size() still failed, that would be more to the
point.

> @@ -102,7 +98,13 @@ main (int argc, char *argv[])
>      exit (EXIT_FAILURE);
>    }
> 
> -  /* info for a different export */
> +  /* info on something not present fails */
> +  if (nbd_opt_info (nbd) != -1) {
> +    fprintf (stderr, "expecting error for opt_info\n");
> +    exit (EXIT_FAILURE);
> +  }
> +

Yes, this makes sense, assuming the previous point is "good enough".

> +  /* info for a different export; idempotent name change is no-op */
>    if (nbd_set_export_name (nbd, "b") == -1) {
>      fprintf (stderr, "%s\n", nbd_get_error ());
>      exit (EXIT_FAILURE);
> @@ -111,6 +113,10 @@ main (int argc, char *argv[])
>      fprintf (stderr, "%s\n", nbd_get_error ());
>      exit (EXIT_FAILURE);
>    }
> +  if (nbd_set_export_name (nbd, "b") == -1) {
> +    fprintf (stderr, "%s\n", nbd_get_error ());
> +    exit (EXIT_FAILURE);
> +  }
>    if ((r = nbd_get_size (nbd)) != 1) {
>      fprintf (stderr, "expecting size of 1, got %" PRId64 "\n", r);
>      exit (EXIT_FAILURE);
> 

This looks OK to me.

Laszlo