[PATCH 7 of 7] extdata: abort if external command exits with non-zero status

[Yuya Nishihara]

On Sun, 01 Oct 2017 17:15:06 +0100, FUJIWARA Katsunori wrote:
> At Sun, 01 Oct 2017 13:00:18 +0100,
> Yuya Nishihara wrote:
> > 
> > # HG changeset patch
> > # User Yuya Nishihara <yuya at tcha.org>
> > # Date 1506856910 -3600
> > #      Sun Oct 01 12:21:50 2017 +0100
> > # Node ID 86c51cf6c4ff8a9a01e34e365c8fbc50415d072e
> > # Parent  b3a36705720f5ed1e7cc5129b27450ca59c7952b
> > extdata: abort if external command exits with non-zero status
> > 
> > It could be a warning, but a warning in template output would be unreadable.
> 
> > diff --git a/tests/test-extdata.t b/tests/test-extdata.t
> > --- a/tests/test-extdata.t
> > +++ b/tests/test-extdata.t
> > @@ -12,6 +12,7 @@ test revset support
> >    > filedata = file:extdata.txt
> >    > notes = notes.txt
> >    > shelldata = shell:cat extdata.txt | grep 2
> 
> Just nit:
> 
> I sometime forget that filtering by grep might cause non-zero exit
> code. So, hint like "use `| grep PATTERN | cat` to allow empty
> external data" or so will prevent me from falling into a pitfall in
> the future :-)

Good catch. So it might not be ideal to check the exit code by default.