Re: [PATCH v2 2/2] builtins: kill: Do not signal current process group when pid is empty

[Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx>]

Chris Down wrote on Sat, Feb 15, 2020 at 20:21:09 -0400:
> 1. Add special handling to `kill` to avoid this case. See this patch[0]
>    for a version that does that.

> 0: https://www.zsh.org/mla/workers/2020/msg00251.html

Suggest to state "workers/45426" next to the link: that's how we customarily
refer to mailing lists posts.  The number comes from the X-Seq header and is
shown in the archives too.

> +++ b/Test/B11kill.ztst
> @@ -50,3 +50,15 @@
>    kill -INT
>  1:kill with sigspec only
>  ?(eval):kill:1: not enough arguments
> +
> +# Regression tests: `kill ''` should not result in `kill 0`.
> +
> +  trap 'exit 19' TERM
> +  kill ''
> +1:Plain kill with empty pid should not send signal to current process group
> +?(eval):kill:2: illegal pid: 

Should this test use a subshell so as not to kill the test suite process in
case the bug regresses?

Personally, I'm partial to first adding commits in "expected to fail" mode
(using the «f» flag after the expected exit code) and then in a separate commit
fix the bug, since doing so in effect validates the test.  However, I see this
as a nice-to-hvae, not a blocker.

> +  trap 'exit 11' INT
> +  kill -INT ''
> +1:kill with empty pid and sigspec should not send signal to current process group
> +?(eval):kill:2: illegal pid: 

Could you add a comment explaining the magic numbers 11 and 19?

Cheers,

Daniel