set LC_TIME even if locale dir is not present

From: =?UTF-8?q?Matthias=20A=C3=9Fhauer?= <[email protected]>

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.

This leads to a subtle bug where git log --date=format:%c will use C locale instead of the system locale on systems without a valid textdomain directory.

This fixes https://github.com/git-for-windows/git/issues/2959

---
[RFC] set LC_TIME even if locale dir is not present

This is a small bug fix with a large and unwieldy regression test. The whole prepare_time_locale() bit and and the Makefile change is obviously based on prepare_utf8_locale(), but I'm not really happy with it. I'm not even sure how to fully put the issues I have with the test in words.

* I feel like it's not really testing anything on builds without gettext, but adding a GETTEXT prerequisite to a test that something works without gettext is very counter intuitive.

* I'm also not exactly happy about how I choose a locale, but can't think of a better way. It's a reasonable assumption that C locale uses a US date format on most, if not all supported systems, but I have no good way to make sure that the selected locale actually formats dates differently. Defining a custom locale would solve this, but seems like a convoluted way to go about things.

* I'm not entirely happy with testing the output of git log -format=date:%c against the output of the exact same command. I've tried a version of the test based on date(1) and got it working with the GNU version, but looking at the BSD version for our OS X based CI builds and the POSIX spec for that command, they share barely more than their name.

So, looking at the points above, I expect this to take a few re-rolls to get into a reasonable shape.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1189%2Frimrul%2Fdate-format-without-gettext-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1189/rimrul/date-format-without-gettext-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1189

 Makefile                      |  7 +++++++
 gettext.c                     |  3 ++-
 t/t4205-log-pretty-formats.sh | 31 +++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

index e8aba291d7f..ddca29b550b 100644
@@ -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

index bb5ba1fe7cc..2b614c2b8c6 100644
@@ -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");
 

index e448ef2928a..01a1e61ecea 100755
@@ -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
+}
+
 test_expect_success 'set up basic repos' '
 	>foo &&
 	>bar &&

@@ -544,6 +567,14 @@ test_expect_success '--date=human %ad%cd is the same as %ah%ch' '
 	test_cmp expected actual
 '
 
+prepare_time_locale
+test_expect_success TIME_LOCALE '--date=format:%c does not need gettext' '
+	rm -fr no-such-dir &&
+	LC_ALL=$GIT_TEST_TIME_LOCALE git log --date=format:%c HEAD^1..HEAD >expected &&
+	GIT_TEXTDOMAINDIR=no-such-dir LC_ALL=$GIT_TEST_TIME_LOCALE git log --date=format:%c HEAD^1..HEAD >actual &&
+	test_cmp expected actual
+'
+
 # get new digests (with no abbreviations)
 test_expect_success 'set up log decoration tests' '
 	head1=$(git rev-parse --verify HEAD~0) &&

base-commit: abf474a5dd901f28013c52155411a48fd4c09922

gitgitgadget

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...

index bb5ba1fe7cc..9b46c224230 100644
@@ -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);
 }
 

index 0ce1f22eff6..69facd2f8ed 100755
@@ -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 &&

index 515b1af7ed4..886d260082d 100644
@@ -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

index 95851b85b6b..3089bcad37c 100644
@@ -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
 '')