bug#51128: timeout --kill-after=0 seems to not send a kill 0s after the initial signal

[Pádraig Brady]

On 12/10/2021 02:21, Christoph Anton Mitterer wrote:
> Hey.
>
> One more thing on this, since I've just read through:
> https://www.gnu.org/software/coreutils/manual/html_node/timeout-invocation.html#timeout-invocation
>
> That does IMO *not* document the behaviour:
>
> --kill-after=duration says:
> > This option has no effect if timeout’s duration is 0 which disables
> > the associated timeout.
>
> But that's about the timeout from the command itself (i.e. the 1st non-
> option argument), isn't it?
>
> So it means that if I have:
>
> timeout --kill-after=10 0 ./command
>
> There won't be a KILL after 10s, since the duration itself is 0.

Right. That is the behavior.

> There's no word about that --kill-after=0 disabling the KILL in the
> duration != 0 case as in:
> timeout --kill-after=0 10 ./command

Well DURATIONs of 0 were mentioned a little below that.
But it it worth clarifying in the option description itself.
So I'll make the following change:

-This option has no effect if @command{timeout}'s duration is 0 which
-disables the associated timeout.
+This option has no effect if either the main @var{duration}
+of the @command{timeout} command, or the @var{duration} specified
+to this option, is 0.

cheers,
Pádraig