Re: Test failures with GNU grep 2.23

[John Keeping <john@keeping.me.uk>]

On Fri, Feb 19, 2016 at 09:38:17AM -0800, Junio C Hamano wrote:
> Jeff King <peff@peff.net> writes:
> 
> > Yeah, I'd worry that "-a" is not portable. OTOH, BSD grep seems to have
> > it, so between that and GNU, I think most systems are covered. We could
> > do:
> >
> >   test_lazy_prereq GREP_A '
> > 	echo foo | grep -a foo
> >   '
> >
> > and mark these tests with it. I'd also be happy to skip that step and
> > just do it if and when somebody actually complains about a system
> > without it (I wouldn't be surprised if most people on antique systems
> > end up installing GNU grep anyway).
> >
> > Another option might be using "sed -ne '/^author/p'" or similar. But
> > that may very well just be trading one portability problem for another.
> 
> Would $PERL help, I wonder?

I suspect that any grep that lacks "-a" also lacks binary file handling
that will break these tests.  I found a Solaris grep that doesn't
support "-a" and it treats these files as text.

>From that perspective, it would be better to have a central place that
deals with figuring out how to get grep to work for us.  Perhaps we need
test_grep to get this right.  We already have test_cmp_bin() as a thin
wrapper around cmp so I don't think this is completely unprecedented.