Re: [PATCH v3] grep: correctly identify utf-8 characters with \{b,w} in -P

From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Carlo Arenas <carenas@gmail.com>,
	git@vger.kernel.org, Diomidis Spinellis <dds@aueb.gr>
Subject: Re: [PATCH v3] grep: correctly identify utf-8 characters with \{b,w} in -P
Date: Thu, 19 Jan 2023 00:06:43 +0100	[thread overview]
Message-ID: <230119.86cz7bwign.gmgdl@evledraar.gmail.com> (raw)
In-Reply-To: <xmqq7cxj6chn.fsf@gitster.g>

On Wed, Jan 18 2023, Junio C Hamano wrote:

> Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
>
>>> GNU grep -P has no knob and would likely never have one.
>>
>> I think the general knob in not just GNU grep but GNU utils and the
>> wider *nix landscape is "tweak your LC_ALL and/or other locale
>> varibales".
>>
>> Which works for it, and will work for us once we're using PCRE2_UCP too.
>>
>>> So for now, I think we should acknowledge the bug, provide an option
>>> for people that might need the fix, and fix all other problems we
>>> have, which will include changes in PCRE2 as well to better fit our
>>> use case.
>>
>> Hrm, what are those PCRE2 changes? The one I saw so far (or was it a
>> proposal) was to just make its "grep" utility use the PCRE2_UCP like GNU
>> grep is now doing in its unreleased version in its git repo...
>
> Yeah, I didn't understand Carlo's comment in that paragraph at all.
>
> In short, it sounds to me that the earlier one that added PCRE2_UCP
> unconditionally would be the best alternative among those that have
> been discussed.

I agree.