Re: [PATCH v13 3/3] grep/pcre2: fix an edge case concerning ascii patterns and UTF-8 data

From: Carlo Arenas <carenas@gmail.com>
Date: Nov 17, 2021, 21:53 UTC
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