bug#41099: 28.0.50; TRAMP process-file ignores exit status of remote process

[Philipp Stephani <p.stephani2@gmail.com>]

Am Sa., 16. Mai 2020 um 14:19 Uhr schrieb Michael Albinus
<michael.albinus@gmx.de>:
>
> Dmitry Gutov <dgutov@yandex.ru> writes:
>
> > Hi Michael,
>
> Hi Dmitry,
>
> > On 14.05.2020 18:49, Michael Albinus wrote:
> >> I understand (and sympathize) both positions. However, Tramp has
> >> returned for decades no strings for process-file, so I don't expect any
> >> code in the wild which expects this.
> >
> > But is there code in the wild that expects the _current_ behavior?
>
> Don't know. But at least Philipp has reported this inconsistency, so
> there are prople who care.

To be fair, I care far more about the initial bug report (correct
treatment of exit codes below 128). Many programs follow the
convention to treat small nonzero exit codes as "expected" errors
(e.g. grep: 1 means no match found) and higher exit codes as
"unexpected" errors. In that light a distinction between small exit
codes is more important than trying to achieve 100% correctness when
it comes to signals. So I'm definitely fine with adding a
customization option: anything better would likely be more complex
than is warranted.