On 24/01/2021 11:48, Ævar Arnfjörð Bjarmason wrote:
> Improve the support for invalid UTF-8 haystacks given a non-ASCII
> needle when using the PCREv2 backend.
>
> This is a more complete fix for a bug I started to fix in
> 870eea8166 (grep: do not enter PCRE2_UTF mode on fixed matching,
> 2019-07-26), now that PCREv2 has the PCRE2_MATCH_INVALID_UTF mode we
> can make use of it.
>
> This fixes the sort of case described in 8a5999838e (grep: stess test
> PCRE v2 on invalid UTF-8 data, 2019-07-26), i.e.:
>
> - The subject string is non-ASCII (e.g. "ævar")
> - We're under a is_utf8_locale(), e.g. "en_US.UTF-8", not "C"
> - We are using --ignore-case, or we're a non-fixed pattern
>
> If those conditions were satisfied and we matched found non-valid
> UTF-8 data PCREv2 might bark on it, in practice this only happened
> under the JIT backend (turned on by default on most platforms).
>
> Ultimately this fixes a "regression" in b65abcafc7 ("grep: use PCRE v2
> for optimized fixed-string search", 2019-07-01), I'm putting that in
> scare-quotes because before then we wouldn't properly support these
> complex case-folding, locale etc. cases either, it just broke in
> different ways.
>
> There was a bug related to this the PCRE2_NO_START_OPTIMIZE flag fixed
> in PCREv2 10.36. It can be worked around by setting the
> PCRE2_NO_START_OPTIMIZE flag. Let's do that in those cases, and add
> tests for the bug.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
> ---
> Makefile | 1 +
> grep.c | 8 +++++-
> grep.h | 4 +++
> t/helper/test-pcre2-config.c | 12 +++++++++
> t/helper/test-tool.c | 1 +
> t/helper/test-tool.h | 1 +
> t/t7812-grep-icase-non-ascii.sh | 46 ++++++++++++++++++++++++++++++++-
> 7 files changed, 71 insertions(+), 2 deletions(-)
> create mode 100644 t/helper/test-pcre2-config.c
>
> diff --git a/Makefile b/Makefile
> index 4edfda3e00..42a7ed96e2 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -722,6 +722,7 @@ TEST_BUILTINS_OBJS += test-online-cpus.o
> TEST_BUILTINS_OBJS += test-parse-options.o
> TEST_BUILTINS_OBJS += test-parse-pathspec-file.o
> TEST_BUILTINS_OBJS += test-path-utils.o
> +TEST_BUILTINS_OBJS += test-pcre2-config.o
> TEST_BUILTINS_OBJS += test-pkt-line.o
> TEST_BUILTINS_OBJS += test-prio-queue.o
> TEST_BUILTINS_OBJS += test-proc-receive.o
> diff --git a/grep.c b/grep.c
> index efeb6dc58d..e329f19877 100644
> --- a/grep.c
> +++ b/grep.c
> @@ -492,7 +492,13 @@ static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt
> }
> if (!opt->ignore_locale && is_utf8_locale() && has_non_ascii(p->pattern) &&
> !(!opt->ignore_case && (p->fixed || p->is_fixed)))
> - options |= PCRE2_UTF;
> + options |= (PCRE2_UTF | PCRE2_MATCH_INVALID_UTF);
> +
> + if (PCRE2_MATCH_INVALID_UTF &&
> + options & (PCRE2_UTF | PCRE2_CASELESS) &&
> + !(PCRE2_MAJOR >= 10 && PCRE2_MAJOR >= 36))
^^^^^^^^^^^^^^^^^^
I assume that this should be s/_MAJOR/_MINOR/. ;-)
> + /* Work around https://bugs.exim.org/show_bug.cgi?id=2642 fixed in 10.36 */
> + options |= PCRE2_NO_START_OPTIMIZE;
>
> p->pcre2_pattern = pcre2_compile((PCRE2_SPTR)p->pattern,
> p->patternlen, options, &error, &erroffset,
ATB,
Ramsay Jones
