Re: [PATCH 2/5] bios-tables-test: fix up DIFF generation

[Laurent Vivier <lvivier@redhat.com>]

On 22/01/2020 09:05, Michael S. Tsirkin wrote:
> Turns out it goes to stdout which is suppressed even with V=1.
> Force DIFF output to stderr to make it visible.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  tests/qtest/bios-tables-test.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/bios-tables-test.c b/tests/qtest/bios-tables-test.c
> index 6b5f24bf62..c8db2839b2 100644
> --- a/tests/qtest/bios-tables-test.c
> +++ b/tests/qtest/bios-tables-test.c
> @@ -463,13 +463,18 @@ static void test_acpi_asl(test_data *data)
>                          "Actual [asl:%s, aml:%s], Expected [asl:%s, aml:%s].\n",
>                          exp_sdt->aml, sdt->asl_file, sdt->aml_file,
>                          exp_sdt->asl_file, exp_sdt->aml_file);
> +                fflush(stderr);
>                  if (getenv("V")) {
>                      const char *diff_cmd = getenv("DIFF");
>                      if (diff_cmd) {
> -                        int ret G_GNUC_UNUSED;
>                          char *diff = g_strdup_printf("%s %s %s", diff_cmd,
>                              exp_sdt->asl_file, sdt->asl_file);
> +                        int out = dup(STDOUT_FILENO);
> +                        int ret G_GNUC_UNUSED;
> +
> +                        dup2(STDERR_FILENO, STDOUT_FILENO);
>                          ret = system(diff) ;
> +                        dup2(out, STDOUT_FILENO);

I think you need a "close(out)" here.

Thanks,
Laurent