Re: [PATCH] set LC_TIME even if locale dir is not present

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Sun, Mar 27 2022, Matthias Aßhauer via GitGitGadget wrote:

> From: =?UTF-8?q?Matthias=20A=C3=9Fhauer?= <mha1993@live.de>
>
> Since Commit aa1462c (introduce "format" date-mode, 2015-06-25) git log can
> pass user specified format strings directly to strftime(). One special
> format string we explicitly mention in our documentation is %c, which
> depends on the system locale. To accommodate for %c we added a call to
> setlocale() in git_setup_gettext().
>
> In Commit cc5e1bf (gettext: avoid initialization if the locale dir is not
> present, 2018-04-21) we added an early exit to git_setup_gettext() in case
> no textdomain directory is present. This early exit is so early, that we
> don't even set the locale for %c in that case, despite strftime() not
> needing the textdomain directory at all.

Thanks for tracking this down. This commit & end-state looks good to me,
I just have comments about the implementation below, i.e. you're doing
more work than you need to, some of this we have test infrastructure
already...

> diff --git a/Makefile b/Makefile
> index e8aba291d7f..ddca29b550b 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -410,6 +410,10 @@ include shared.mak
>  # If it isn't set, fallback to $LC_ALL, $LANG or use the first utf-8
>  # locale returned by "locale -a".
>  #
> +# Define GIT_TEST_TIME_LOCALE to preferred non-us locale for testing.
> +# If it isn't set, fallback to $LC_ALL, $LANG or use the first non-us
> +# locale returned by "locale -a".
> +#
>  # Define HAVE_CLOCK_GETTIME if your platform has clock_gettime.
>  #
>  # Define HAVE_CLOCK_MONOTONIC if your platform has CLOCK_MONOTONIC.
> @@ -2862,6 +2866,9 @@ ifdef GIT_TEST_CMP_USE_COPIED_CONTEXT
>  endif
>  ifdef GIT_TEST_UTF8_LOCALE
>  	@echo GIT_TEST_UTF8_LOCALE=\''$(subst ','\'',$(subst ','\'',$(GIT_TEST_UTF8_LOCALE)))'\' >>$@+
> +endif
> +ifdef GIT_TEST_TIME_LOCALE
> +	@echo GIT_TEST_TIME_LOCALE=\''$(subst ','\'',$(subst ','\'',$(GIT_TEST_TIME_LOCALE)))'\' >>$@+
>  endif
>  	@echo NO_GETTEXT=\''$(subst ','\'',$(subst ','\'',$(NO_GETTEXT)))'\' >>$@+
>  ifdef GIT_PERF_REPEAT_COUNT

You won't need this, more later...

> diff --git a/gettext.c b/gettext.c
> index bb5ba1fe7cc..2b614c2b8c6 100644
> --- a/gettext.c
> +++ b/gettext.c
> @@ -107,6 +107,8 @@ void git_setup_gettext(void)
>  	const char *podir = getenv(GIT_TEXT_DOMAIN_DIR_ENVIRONMENT);
>  	char *p = NULL;
>  
> +	setlocale(LC_TIME, "");
> +
>  	if (!podir)
>  		podir = p = system_path(GIT_LOCALE_PATH);
>  
> @@ -117,7 +119,6 @@ void git_setup_gettext(void)
>  
>  	bindtextdomain("git", podir);
>  	setlocale(LC_MESSAGES, "");
> -	setlocale(LC_TIME, "");
>  	init_gettext_charset("git");
>  	textdomain("git");
>  
> diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
> index e448ef2928a..01a1e61ecea 100755
> --- a/t/t4205-log-pretty-formats.sh
> +++ b/t/t4205-log-pretty-formats.sh
> @@ -25,6 +25,29 @@ commit_msg () {
>  	fi
>  }
>  
> +prepare_time_locale () {
> +	if test -z "$GIT_TEST_TIME_LOCALE"
> +	then
> +		case "${LC_ALL:-$LANG}" in
> +		C | C.* | POSIX | POSIX.* | en_US | en_US.* )
> +			GIT_TEST_TIME_LOCALE=$(locale -a | sed -n '/^\(C\|POSIX\|en_US\)/I !{
> +				p
> +				q
> +			}')
> +			;;
> +		*)
> +			GIT_TEST_TIME_LOCALE="${LC_ALL:-$LANG}"
> +			;;
> +		esac
> +	fi
> +	if test -n "$GIT_TEST_TIME_LOCALE"
> +	then
> +		test_set_prereq TIME_LOCALE
> +	else
> +		say "# No non-us locale available, some tests are skipped"
> +	fi
> +}
> +

And this setup we do already elsewhere.

I think the below would be a good candidate to squash into this. The C
change doesn't change the behavior from your version, but I think it's
good to take the change here about being explicit what we do and don't
seup with/without a podir.

Your prepare_time_locale() is then duplicating lib-gettext.sh, the below
shows a replacement for your test piggy-backing on existing test infra.

I was then worried that we'd introduced a regression in cc5e1bf in
assuming that we didn't need to setlocale(LC_MESSAGES) just because we
didn't have a podir, because the C library might have some, but the
below test passe for me on linux+glibc.

Maybe there's still a regression there, I'm not sure. Perhaps it's also
good to drop that "optimization" on non-Windows platforms?

diff --git a/gettext.c b/gettext.c
index bb5ba1fe7cc..9b46c224230 100644
--- a/gettext.c
+++ b/gettext.c
@@ -102,25 +102,34 @@ static void init_gettext_charset(const char *domain)
 		setlocale(LC_CTYPE, "C");
 }
 
+static void git_setup_gettext_no_podir(void)
+{
+	setlocale(LC_TIME, "");
+}
+
+static void git_setup_gettext_podir(const char *podir)
+{
+	bindtextdomain("git", podir);
+	setlocale(LC_MESSAGES, "");
+	init_gettext_charset("git");
+	textdomain("git");
+}
+
 void git_setup_gettext(void)
 {
 	const char *podir = getenv(GIT_TEXT_DOMAIN_DIR_ENVIRONMENT);
 	char *p = NULL;
 
+	git_setup_gettext_no_podir();
+
 	if (!podir)
 		podir = p = system_path(GIT_LOCALE_PATH);
 
-	if (!is_directory(podir)) {
-		free(p);
-		return;
-	}
-
-	bindtextdomain("git", podir);
-	setlocale(LC_MESSAGES, "");
-	setlocale(LC_TIME, "");
-	init_gettext_charset("git");
-	textdomain("git");
+	if (!is_directory(podir))
+		goto done;
 
+	git_setup_gettext_podir(podir);
+done:
 	free(p);
 }
 
diff --git a/t/t0203-gettext-setlocale-sanity.sh b/t/t0203-gettext-setlocale-sanity.sh
index 0ce1f22eff6..69facd2f8ed 100755
--- a/t/t0203-gettext-setlocale-sanity.sh
+++ b/t/t0203-gettext-setlocale-sanity.sh
@@ -23,4 +23,49 @@ test_expect_success GETTEXT_LOCALE 'git show a ISO-8859-1 commit under a UTF-8 l
 	grep -q "iso-utf8-commit" out
 '
 
+test_expect_success GETTEXT_LOCALE 'the %c date format works even without a localedir (LC_TIME)' '
+	test_when_finished "rm -rf empty" &&
+	mkdir empty &&
+	LANGUAGE=is LC_ALL="$is_IS_locale" GIT_TEXTDOMAINDIR="$PWD/empty" \
+		git log --pretty=format:%ad --date=format:%c HEAD^1..HEAD >actual &&
+
+	# Avoid testing the raw format (it might differ?). But
+	# Thursday is Fimmtudagur in Icelandic, so grepping "fim" is
+	# pretty certain to test that the locale was used.
+	grep -iF fim actual
+'
+
+test_lazy_prereq GETTEXT_HAVE_STRERROR_TRANSLATED '
+	test_have_prereq GETTEXT_LOCALE &&
+	test_have_prereq POSIXPERM &&
+
+	test_when_finished "rm -f file" &&
+	>file &&
+
+	# German is more likely to have a strerror() translation
+	test_must_fail git init file 2>loc-C &&
+	grep "cannot mkdir" loc-C &&
+	test_must_fail env \
+		LANGUAGE=de LC_ALL="de_DE.utf8" \
+		git init file 2>loc-de &&
p+	! grep "cannot mkdir" loc-de
+
+'
+
+test_expect_success GETTEXT_LOCALE,GETTEXT_HAVE_STRERROR_TRANSLATED \
+	'LC_MESSAGES is set up without a localedir (for strerror())' '
+	test_when_finished "rm -f file" &&
+	>file &&
+	test_when_finished "rm -rf no-domain" &&
+	mkdir no-domain &&
+
+	test_must_fail git init file 2>loc-C &&
+	test_must_fail env \
+		LANGUAGE=de LC_ALL="de_DE.utf8" \
+		NO_SET_GIT_TEXTDOMAINDIR=StopDoingThatInBinWrappers \
+		GIT_TEXTDOMAINDIR="$PWD/no-domain" \
+		git init file 2>loc-de-no-textdomain &&
+	! test_cmp loc-C loc-de-no-textdomain
+'
+
 test_done
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 515b1af7ed4..886d260082d 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1428,6 +1428,8 @@ else # normal case, use ../bin-wrappers only unless $with_dashes:
 			fi
 			with_dashes=t
 		fi
+		GIT_RUNING_TEST_LIB_SH=t
+		export GIT_RUNING_TEST_LIB_SH
 		PATH="$git_bin_dir:$PATH"
 	fi
 	GIT_EXEC_PATH=$GIT_BUILD_DIR
diff --git a/wrap-for-bin.sh b/wrap-for-bin.sh
index 95851b85b6b..3089bcad37c 100644
--- a/wrap-for-bin.sh
+++ b/wrap-for-bin.sh
@@ -15,10 +15,14 @@ else
 	export GIT_TEMPLATE_DIR
 fi
 GITPERLLIB='@@BUILD_DIR@@/perl/build/lib'"${GITPERLLIB:+:$GITPERLLIB}"
-GIT_TEXTDOMAINDIR='@@BUILD_DIR@@/po/build/locale'
+if test -z "$NO_SET_GIT_TEXTDOMAINDIR"
+then
+	GIT_TEXTDOMAINDIR='@@BUILD_DIR@@/po/build/locale'
+	export GIT_TEXTDOMAINDIR
+fi
 PATH='@@BUILD_DIR@@/bin-wrappers:'"$PATH"
 
-export GIT_EXEC_PATH GITPERLLIB PATH GIT_TEXTDOMAINDIR
+export GIT_EXEC_PATH GITPERLLIB PATH
 
 case "$GIT_DEBUGGER" in
 '')