I've recently done some bug-report maintenance about a set of GNU grep
bug reports related to whether whether "grep -P '\d'" should match
non-ASCII digits, and have some thoughts about coordinating GNU grep
with git grep in this department.
GNU Bug#62605[1] "`[\d]` does not work with PCRE" has been fixed on
Savannah's copy of GNU grep, and some sort of fix should appear in the
next grep release. However, I'm leaving the GNU grep bug report open for
now because it's related to Bug#60690[2] "[PATCH v2] grep: correctly
identify utf-8 characters with \{b,w} in -P" and to Bug#62552[3] "Bug
found in latest stable release v3.10 of grep". I merged these related
bug reports, and the oldest one, Bug#60690, is now the representative
displayed in the GNU grep bug list[4].
For this set of grep bug reports there's still a pending issue discussed
in my recent email[5], which proposes a patch so I've tagged Bug#60690
with "patch". The proposal is that GNU grep -P '\d' should revert to the
grep 3.9 behavior, i.e., that in a UTF-8 locale, \d should also match
non-ASCII decimal digits.
In researching this a bit further, I found that on March 23 Git disabled
the use of PCRE2_UCP in PCRE2 10.34 or earlier[6], due to a PCRE2 bug
that can cause a crash when PCRE2_UCP is used[7]. A bug fix[8] should
appear in the next PCRE2 release.
When PCRE2 10.35 comes out, it appears that 'git grep -P' will behave
like 'grep -P' only if GNU grep adopts something like the solution
proposed in [5].
[1]: https://bugs.gnu.org/62605
[2]: https://bugs.gnu.org/60690
[3]: https://bugs.gnu.org/62552
[4]: https://debbugs.gnu.org/cgi/pkgreport.cgi?package=grep
[5]: https://lists.gnu.org/archive/html/grep-devel/2023-04/msg00004.html
[6]:
https://github.com/git/git/commit/14b9a044798ebb3858a1f1a1377309a3d6054ac8
[7]:
https://lore.kernel.org/git/7e83daa1-f9a9-4151-8d07-d80ea6d59...@clumio.com/
[8]:
https://github.com/git/git/commit/14b9a044798ebb3858a1f1a1377309a3d6054ac8
