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

[Junio C Hamano <gitster@pobox.com>]

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

> On Thu, Nov 18 2021, René Scharfe wrote:
>>
>> Makes sense to me.  It gives a better starting point to solve the issue
>> afresh without getting entangled in mind-melting boolean expressions.
>
> Yes, agreed. As noted I haven't had time to dig deeply into this, but
> from what I've seen so far there doesn't seem to be any obvious way
> forward in terms of a quick fix.
>
> I thought perhaps your patch would be that (but I haven't looked into it
> carefully enough), but since you're on-board with reverting & retrying.

OK.  Here is what I'll queue 'master', in the hope of later merging
down and be part of v2.34.1.

Thanks, all.

----- >8 --------- >8 --------- >8 --------- >8 -----
Subject: [PATCH] Revert "grep/pcre2: fix an edge case concerning ascii patterns and UTF-8 data"

This reverts commit ae39ba431ab861548eb60b4bd2e1d8b8813db76f, as it
breaks "grep" when looking for a string in non UTF-8 haystack, when
linked with certain versions of PCREv2 library.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 grep.c                          |  6 ++---
 t/t7812-grep-icase-non-ascii.sh | 48 ---------------------------------
 2 files changed, 2 insertions(+), 52 deletions(-)

diff --git a/grep.c b/grep.c
index f6e113e9f0..fe847a0111 100644
--- a/grep.c
+++ b/grep.c
@@ -382,10 +382,8 @@ static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt
 		}
 		options |= PCRE2_CASELESS;
 	}
-	if ((!opt->ignore_locale && !has_non_ascii(p->pattern)) ||
-	    (!opt->ignore_locale && is_utf8_locale() &&
-	     has_non_ascii(p->pattern) && !(!opt->ignore_case &&
-					    (p->fixed || p->is_fixed))))
+	if (!opt->ignore_locale && is_utf8_locale() && has_non_ascii(p->pattern) &&
+	    !(!opt->ignore_case && (p->fixed || p->is_fixed)))
 		options |= (PCRE2_UTF | PCRE2_MATCH_INVALID_UTF);
 
 #ifdef GIT_PCRE2_VERSION_10_36_OR_HIGHER
diff --git a/t/t7812-grep-icase-non-ascii.sh b/t/t7812-grep-icase-non-ascii.sh
index 22487d90fd..e5d1e4ea68 100755
--- a/t/t7812-grep-icase-non-ascii.sh
+++ b/t/t7812-grep-icase-non-ascii.sh
@@ -53,54 +53,6 @@ test_expect_success REGEX_LOCALE 'pickaxe -i on non-ascii' '
 	test_cmp expected actual
 '
 
-test_expect_success GETTEXT_LOCALE,PCRE 'log --author with an ascii pattern on UTF-8 data' '
-	cat >expected <<-\EOF &&
-	Author: <BOLD;RED>À Ú Thor<RESET> <author@example.com>
-	EOF
-	test_write_lines "forth" >file4 &&
-	git add file4 &&
-	git commit --author="À Ú Thor <author@example.com>" -m sécond &&
-	git log -1 --color=always --perl-regexp --author=".*Thor" >log &&
-	grep Author log >actual.raw &&
-	test_decode_color <actual.raw >actual &&
-	test_cmp expected actual
-'
-
-test_expect_success GETTEXT_LOCALE,PCRE 'log --committer with an ascii pattern on ISO-8859-1 data' '
-	cat >expected <<-\EOF &&
-	Commit:     Ç<BOLD;RED> O Mîtter <committer@example.com><RESET>
-	EOF
-	test_write_lines "fifth" >file5 &&
-	git add file5 &&
-	GIT_COMMITTER_NAME="Ç O Mîtter" &&
-	GIT_COMMITTER_EMAIL="committer@example.com" &&
-	git -c i18n.commitEncoding=latin1 commit -m thïrd &&
-	git -c i18n.logOutputEncoding=latin1 log -1 --pretty=fuller --color=always --perl-regexp --committer=" O.*" >log &&
-	grep Commit: log >actual.raw &&
-	test_decode_color <actual.raw >actual &&
-	test_cmp expected actual
-'
-
-test_expect_success GETTEXT_LOCALE,PCRE 'log --grep with an ascii pattern on UTF-8 data' '
-	cat >expected <<-\EOF &&
-	    sé<BOLD;RED>con<RESET>d
-	EOF
-	git log -1 --color=always --perl-regexp --grep="con" >log &&
-	grep con log >actual.raw &&
-	test_decode_color <actual.raw >actual &&
-	test_cmp expected actual
-'
-
-test_expect_success GETTEXT_LOCALE,PCRE 'log --grep with an ascii pattern on ISO-8859-1 data' '
-	cat >expected <<-\EOF &&
-	    <BOLD;RED>thïrd<RESET>
-	EOF
-	git -c i18n.logOutputEncoding=latin1 log -1 --color=always --perl-regexp --grep="th.*rd" >log &&
-	grep "th.*rd" log >actual.raw &&
-	test_decode_color <actual.raw >actual &&
-	test_cmp expected actual
-'
-
 test_expect_success GETTEXT_LOCALE,LIBPCRE2 'PCRE v2: setup invalid UTF-8 data' '
 	printf "\\200\\n" >invalid-0x80 &&
 	echo "ævar" >expected &&
-- 
2.34.0-202-gd9146917d7