From: Carlo Arenas <carenas@gmail.com>
Date: Wed, 17 Nov 2021 21:53:05 GMT
Subject: Re: [PATCH v13 3/3] grep/pcre2: fix an edge case concerning ascii patterns and UTF-8 data
Message-ID: <CAPUEsph8NMJtK2r_fuT6UPsgmoPAeGVfTLOj8uz6NaOj4UZ1dg@mail.gmail.com>
In-Reply-To: <211117.86y25m5wez.gmgdl@evledraar.gmail.com>

On Wed, Nov 17, 2021 at 1:01 PM Ævar Arnfjörð Bjarmason
<avarab@gmail.com> wrote:
>
> PCRE2_UTF will also matter for literal patterns. Try to peel apart the
> two bytes in "é" and match them under -i with/without PCRE_UTF.

Is there a real use case for why someone would do that? and how is
that "literal" valid UTF to warrant setting PCRE2_UTF?
I would expect that someone including random bytes in the expression
is really more interested in binary matching anyway and the use of -i
with it probably should be an error.

Indeed I suspect the fact that pcre2_compile lets it through might be
a bug in PCRE2

$ pcre2test
PCRE2 version 10.39 2021-10-29
  re> /\303/utf,caseless
data> \303
 0: \x{c3}
data> é
No match

Carlo