bug#20974: Weird newline matching behaviour in --null-data mode

[Norihiro Tanaka]

On Fri, 3 Jul 2015 17:59:19 +0100
Balazs Kezes <address@hidden> wrote:

> I'm running into issues with grep in -z mode. I've managed to minimize
> it into this:
> 
>       $ seq 2 | grep --null-data --quiet '[12].2' ; echo $?
>       0
>       $ seq 2 | grep --null-data --quiet '[1-2].2' ; echo $?
>       1
> 
> I'd expect the two expressions to mean the same. I've tried this with
> the latest version built from the official sources, 2.21. I've also
> found [1] which might be related but it wasn't updated for almost 2
> years. Or is this expected?

$ seq 2 | env LC_ALL=C grep --null-data --quiet '[12].2' ; echo $?
0
$ seq 2 | env LC_ALL=C grep --null-data --quiet '[1-2].2' ; echo $?
0
$ seq 2 | env LC_ALL=en_US.iso88591 grep --null-data --quiet '[12].2' ; echo $?
0
$ seq 2 | env LC_ALL=en_US.iso88591 grep --null-data --quiet '[1-2].2' ; echo $?
1

grep depends on regex for only last case to support collating element,
but regex is not support to substitute NUL for LF as newline character
with --null-data.