Re: Latest snapshot and glibc regex support

[Jim Meyering]

Jim Meyering wrote:
> Matthew Burgess wrote:
>> A while ago Linux From Scratch added the '--without-included-regex'
>> flag to grep's configure invocation in order to fix the behaviour of
>> grep -i' (see http://wiki.linuxfromscratch.org/lfs/changeset/8688).
>
> It's good that you mentioned that configure option.
> I haven't been testing with it, just tried,
> (thus forcing grep to use Fedora 12's glibc-2.11.1-1.x86_64)
> and saw two resulting test failures:
>
>     FAIL: spencer1.sh
>     FAIL: spencer1-locale
>
> The latter test uses the new framework, so I could easily
> see which are failing:
>
>     Spencer test #109 failed (en_US.UTF-8)
>     Spencer test #110 failed (zh_CN)
>     Spencer test #111 failed (fr_FR.UTF-8)

These failures are on the fringe, and independent of locale,
so may not have much of a bearing on which way you go after all.

We expect a reversed range to make grep give a diagnostic and exit 2.
With glibc (--without-included-regex), you get no diagnostic and exit 1.

Using ./configure on an x86_64 system, I get the expected/desired result:

    $ :|./grep -E 'a[b-a]'
    ./grep: Invalid range end
    [Exit 2]

Using ./configure --without-included-regex (i.e., using glibc's regex),
I get this:

    $ :|./grep -E 'a[b-a]'
    [Exit 1]

Hence, as Paolo said, --without-included-regex is best for now.