Re: [PATCH 3/3] pager: properly log pager exit code when signalled

[Junio C Hamano <gitster@pobox.com>]

Ævar Arnfjörð Bjarmason  <avarab@gmail.com> writes:

> When git invokes a pager that exits with non-zero the common case is
> that we'll already return the correct SIGPIPE failure from git itself,
> but the exit code logged in trace2 has always been incorrectly
> reported[1]. Fix that and log the correct exit code in the logs.
>
> Since this gives us something to test outside of our recently-added
> tests needing a !MINGW prerequisite, let's refactor the test to run on
> MINGW and actually check for SIGPIPE outside of MINGW.
>
> The wait_or_whine() is only called with a true "in_signal" from from
> finish_command_in_signal(), which in turn is only used in pager.c.
>
> I'm not quite sure about that BUG() case. Can we have a true in_signal
> and not have a true WIFEXITED(status)? I haven't been able to think of
> a test case for it.
>
> 1. The incorrect logging of the exit code in was seemingly copy/pasted
>    into finish_command_in_signal() in ee4512ed481 (trace2: create new
>    combined trace facility, 2019-02-22)
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>  run-command.c    |  8 +++++--
>  t/t7006-pager.sh | 61 +++++++++++++++++++++++++++++++++++++++++-------
>  2 files changed, 58 insertions(+), 11 deletions(-)
>
> diff --git a/run-command.c b/run-command.c
> index ea4d0fb4b15..10e1c96c2bd 100644
> --- a/run-command.c
> +++ b/run-command.c
> @@ -551,8 +551,12 @@ static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
>  
>  	while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
>  		;	/* nothing */
> -	if (in_signal)
> -		return 0;
> +	if (in_signal && WIFEXITED(status))
> +		return WEXITSTATUS(status);
> +	if (in_signal) {
> +		BUG("was not expecting waitpid() status %d", status);
> +		return -1;
> +	}

Doesn't BUG die, never to return control back to us?  How about
"warning()" or "error()"?