On 23.03.23 17:19, Junio C Hamano wrote:
> Mathias Krause <minipli@xxxxxxxxxxxxxx> writes:
>
>> ... or fall-back to the previous behaviour and
>> ignore Unicode properties (and reintroduce the bug commit acabd2048ee0
>> ("grep: correctly identify utf-8 characters with \{b,w} in -P") wanted
>> to fix).
>>
>> I went with the second option and could confirm the below patch fixes
>> the segfault on Ubuntu 20.04 which is shipping the broken version.
>>
>> Junio, what's your call on it? Below patch or simply a revert of commit
>> acabd2048ee0? Other ideas?
>
> Thanks for all the investigation and a prompt fix. Very much
> appreciated.
As there was the slight chance it could be caused by my grep.c change, I
had the ambition to prove it either way. :D
> As you identified where the breakage ended in the versions of pcre,
> I think that the approach the patch I am responding to takes is more
> sensible than a straight revert.
Ok. It's really unfortunate that PCRE2 has so many bugs we need to work
around :/
> But I somehow suspect that it may be better to have the "workaround"
> independent of the line acabd204 (grep: correctly identify utf-8
> characters with \{b,w} in -P, 2023-01-08) touched, more like how we
> "Work around ... fixed in 10.36".
>
> IOW, not like this
>
>> options |= PCRE2_CASELESS;
>> }
>> - if (!opt->ignore_locale && is_utf8_locale() && !literal)
>> + if (!opt->ignore_locale && is_utf8_locale() && !literal) {
>> options |= (PCRE2_UTF | PCRE2_UCP | PCRE2_MATCH_INVALID_UTF);
>> +#ifndef GIT_PCRE2_VERSION_10_35_OR_HIGHER
>> + /*
>> + * Work around a JIT bug related to invalid Unicode character
>> + * handling fixed in 10.35:
>> + * https://github.com/PCRE2Project/pcre2/commit/c21bd977547d
>> + */
>> + options ^= PCRE2_UCP;
>> +#endif
>> + }
>
> but more like
>
> if (!opt->ignore_locale && is_utf8_locale() && !literal)
> options |= (PCRE2_UTF | PCRE2_UCP | PCRE2_MATCH_INVALID_UTF);
>
> +#ifndef GIT_PCRE2_VERSION_10_35_OR_HIGHER
> + /*
> + * Work around a JIT bug related to invalid Unicode character
> + * handling fixed in 10.35:
> + * https://github.com/PCRE2Project/pcre2/commit/c21bd977547d
> + */
> + options ^= PCRE2_UCP;
> +#endif
> +
> #ifndef GIT_PCRE2_VERSION_10_36_OR_HIGHER
> /* Work around https://bugs.exim.org/show_bug.cgi?id=2642 fixed in 10.36 */
> if (PCRE2_MATCH_INVALID_UTF && options & (PCRE2_UTF | PCRE2_CASELESS))
>
> That way, no matter how we ended up setting the UCP bit in the
> options variable, we would avoid broken UCP handling on problematic
> versions, no?
Ah, sure! It's no issue with the current code base, as PCRE2_UCP only
gets set in that branch, but there's no need to narrow the workaround to
it as well.
I'll send a v2 in a few!
Thanks,
Mathias
>
>> #ifndef GIT_PCRE2_VERSION_10_36_OR_HIGHER
>> /* Work around https://bugs.exim.org/show_bug.cgi?id=2642 fixed in 10.36 */
>> diff --git a/grep.h b/grep.h
>> index 6075f997e68f..c59592e3bdba 100644
>> --- a/grep.h
>> +++ b/grep.h
>> @@ -7,6 +7,9 @@
>> #if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 36) || PCRE2_MAJOR >= 11
>> #define GIT_PCRE2_VERSION_10_36_OR_HIGHER
>> #endif
>> +#if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 35) || PCRE2_MAJOR >= 11
>> +#define GIT_PCRE2_VERSION_10_35_OR_HIGHER
>> +#endif
>> #if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 34) || PCRE2_MAJOR >= 11
>> #define GIT_PCRE2_VERSION_10_34_OR_HIGHER
>> #endif
