On Fri, Nov 1, 2013 at 8:55 AM, Stefano Lattarini
<stefano.lattarini@gmail.com> wrote:
> This probably calls for a two patch series: the first introducing the test
> as
> an XFAIL, the second fixing the bug without touching the tests, and
> verifying
> that the test succeeds.

That seems like overkill, and unnecessary churn in git.  Usually, once I
have a complete(including test case) and committed-but-not-pushed patch ,
I either arrange to run the test against the previous binary by replacing
src/grep with the grep from my path, or (probably better) temporarily
backing out the fix, e.g., with "git log -1 -p src/dfa.c|patch -R -p1"
and ensuring that "make check" fails.

> Maybe you could even amend the test to run with all of the default locale,
> the
> en_US.UTF-8 locale, and the C locale.  Possibly overly paranoid, but the
> enhancement would be trivial, so why not get the extra coverage anyway?

That seems worthwhile.
The default locale is set via tests/Makefile.am to LC_ALL=C, so I have
done this: