i18n: add infrastructure for translating Git with gettext

Change the skeleton implementation of i18n in Git to one that can show
localized strings to users for our C, Shell and Perl programs using
either GNU libintl or the Solaris gettext implementation.

This new internationalization support is enabled by default. If
gettext isn't available, or if Git is compiled with
NO_GETTEXT=YesPlease, Git falls back on its current behavior of
showing interface messages in English. When using the autoconf script
we'll auto-detect if the gettext libraries are installed and act
appropriately.

This change is somewhat large because as well as adding a C, Shell and
Perl i18n interface we're adding a lot of tests for them, and for
those tests to work we need a skeleton PO file to actually test
translations. A minimal Icelandic translation is included for this
purpose. Icelandic includes multi-byte characters which makes it easy
to test various edge cases, and it's a language I happen to
understand.

The rest of the commit message goes into detail about various
sub-parts of this commit.

= Installation

Gettext .mo files will be installed and looked for in the standard
$(prefix)/share/locale path. GIT_TEXTDOMAINDIR can also be set to
override that, but that's only intended to be used to test Git itself.

= Perl

Perl code that's to be localized should use the new Git::I18n
module. It imports a __ function into the caller's package by default.

Instead of using the high level Locale::TextDomain interface I've
opted to use the low-level (equivalent to the C interface)
Locale::Messages module, which Locale::TextDomain itself uses.

Locale::TextDomain does a lot of redundant work we don't need, and
some of it would potentially introduce bugs. It tries to set the
$TEXTDOMAIN based on package of the caller, and has its own
hardcoded paths where it'll search for messages.

I found it easier just to completely avoid it rather than try to
circumvent its behavior. In any case, this is an issue wholly
internal Git::I18N. Its guts can be changed later if that's deemed
necessary.

See <AANLkTilYD_NyIZMyj9dHtVk-ylVBfvyxpCC7982LWnVd@mail.gmail.com> for
a further elaboration on this topic.

= Shell

Shell code that's to be localized should use the git-sh-i18n
library. It's basically just a wrapper for the system's gettext.sh.

If gettext.sh isn't available we'll fall back on gettext(1) if it's
available. The latter is available without the former on Solaris,
which has its own non-GNU gettext implementation. We also need to
emulate eval_gettext() there.

If neither are present we'll use a dumb printf(1) fall-through
wrapper.

= About libcharset.h and langinfo.h

We use libcharset to query the character set of the current locale if
it's available. I.e. we'll use it instead of nl_langinfo if
HAVE_LIBCHARSET_H is set.

The GNU gettext manual recommends using langinfo.h's
nl_langinfo(CODESET) to acquire the current character set, but on
systems that have libcharset.h's locale_charset() using the latter is
either saner, or the only option on those systems.

GNU and Solaris have a nl_langinfo(CODESET), FreeBSD can use either,
but MinGW and some others need to use libcharset.h's locale_charset()
instead.

=Credits

This patch is based on work by Jeff Epler <jepler@unpythonic.net> who
did the initial Makefile / C work, and a lot of comments from the Git
mailing list, including Jonathan Nieder, Jakub Narebski, Johannes
Sixt, Erik Faye-Lund, Peter Krefting, Junio C Hamano, Thomas Rast and
others.

[jc: squashed a small Makefile fix from Ramsay]

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

12 files changed, 512 insertions, 2 deletions

diff --git a/t/lib-gettext.sh b/t/lib-gettext.sh
new file mode 100644
index 000000000..0f76f6cdc
--- /dev/null
+++ b/t/lib-gettext.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Ævar Arnfjörð Bjarmason
+#
+
+. ./test-lib.sh
+
+GIT_TEXTDOMAINDIR="$GIT_BUILD_DIR/po/build/locale"
+GIT_PO_PATH="$GIT_BUILD_DIR/po"
+export GIT_TEXTDOMAINDIR GIT_PO_PATH
+
+. "$GIT_BUILD_DIR"/git-sh-i18n
+
+if test_have_prereq GETTEXT && ! test_have_prereq GETTEXT_POISON
+then
+	# is_IS.UTF-8 on Solaris and FreeBSD, is_IS.utf8 on Debian
+	is_IS_locale=$(locale -a | sed -n '/^is_IS\.[uU][tT][fF]-*8$/{
+		p
+		q
+	}')
+	# is_IS.ISO8859-1 on Solaris and FreeBSD, is_IS.iso88591 on Debian
+	is_IS_iso_locale=$(locale -a | sed -n '/^is_IS\.[iI][sS][oO]8859-*1$/{
+		p
+		q
+	}')
+
+	# Export them as an environment variable so the t0202/test.pl Perl
+	# test can use it too
+	export is_IS_locale is_IS_iso_locale
+
+	if test -n "$is_IS_locale" &&
+		test $GIT_INTERNAL_GETTEXT_SH_SCHEME != "fallthrough"
+	then
+		# Some of the tests need the reference Icelandic locale
+		test_set_prereq GETTEXT_LOCALE
+
+		# Exporting for t0202/test.pl
+		GETTEXT_LOCALE=1
+		export GETTEXT_LOCALE
+		say "# lib-gettext: Found '$is_IS_locale' as an is_IS UTF-8 locale"
+	else
+		say "# lib-gettext: No is_IS UTF-8 locale available"
+	fi
+
+	if test -n "$is_IS_iso_locale" &&
+		test $GIT_INTERNAL_GETTEXT_SH_SCHEME != "fallthrough"
+	then
+		# Some of the tests need the reference Icelandic locale
+		test_set_prereq GETTEXT_ISO_LOCALE
+
+		say "# lib-gettext: Found '$is_IS_iso_locale' as an is_IS ISO-8859-1 locale"
+	else
+		say "# lib-gettext: No is_IS ISO-8859-1 locale available"
+	fi
+fi
diff --git a/t/t0200-gettext-basic.sh b/t/t0200-gettext-basic.sh
new file mode 100755
index 000000000..8853d8afb
--- /dev/null
+++ b/t/t0200-gettext-basic.sh
@@ -0,0 +1,108 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Ævar Arnfjörð Bjarmason
+#
+
+test_description='Gettext support for Git'
+
+. ./lib-gettext.sh
+
+test_expect_success "sanity: \$GIT_INTERNAL_GETTEXT_SH_SCHEME is set (to $GIT_INTERNAL_GETTEXT_SH_SCHEME)" '
+    test -n "$GIT_INTERNAL_GETTEXT_SH_SCHEME"
+'
+
+test_expect_success 'sanity: $TEXTDOMAIN is git' '
+    test $TEXTDOMAIN = "git"
+'
+
+test_expect_success 'xgettext sanity: Perl _() strings are not extracted' '
+    ! grep "A Perl string xgettext will not get" "$GIT_PO_PATH"/is.po
+'
+
+test_expect_success 'xgettext sanity: Comment extraction with --add-comments' '
+    grep "TRANSLATORS: This is a test" "$TEST_DIRECTORY"/t0200/* | wc -l >expect &&
+    grep "TRANSLATORS: This is a test" "$GIT_PO_PATH"/is.po  | wc -l >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success 'xgettext sanity: Comment extraction with --add-comments stops at statements' '
+    ! grep "This is a phony" "$GIT_PO_PATH"/is.po &&
+    ! grep "the above comment" "$GIT_PO_PATH"/is.po
+'
+
+test_expect_success GETTEXT 'sanity: $TEXTDOMAINDIR exists without NO_GETTEXT=YesPlease' '
+    test -d "$TEXTDOMAINDIR" &&
+    test "$TEXTDOMAINDIR" = "$GIT_TEXTDOMAINDIR"
+'
+
+test_expect_success GETTEXT 'sanity: Icelandic locale was compiled' '
+    test -f "$TEXTDOMAINDIR/is/LC_MESSAGES/git.mo"
+'
+
+# TODO: When we have more locales, generalize this to test them
+# all. Maybe we'll need a dir->locale map for that.
+test_expect_success GETTEXT_LOCALE 'sanity: gettext("") metadata is OK' '
+    # Return value may be non-zero
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "" >zero-expect &&
+    grep "Project-Id-Version: Git" zero-expect &&
+    grep "Git Mailing List <git@vger.kernel.org>" zero-expect &&
+    grep "Content-Type: text/plain; charset=UTF-8" zero-expect &&
+    grep "Content-Transfer-Encoding: 8bit" zero-expect
+'
+
+test_expect_success GETTEXT_LOCALE 'sanity: gettext(unknown) is passed through' '
+    printf "This is not a translation string"  >expect &&
+    gettext "This is not a translation string" >actual &&
+    eval_gettext "This is not a translation string" >actual &&
+    test_cmp expect actual
+'
+
+# xgettext from C
+test_expect_success GETTEXT_LOCALE 'xgettext: C extraction of _() and N_() strings' '
+    printf "TILRAUN: C tilraunastrengur" >expect &&
+    printf "\n" >>expect &&
+    printf "Sjá '\''git help SKIPUN'\'' til að sjá hjálp fyrir tiltekna skipun." >>expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: A C test string" >actual &&
+    printf "\n" >>actual &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "See '\''git help COMMAND'\'' for more information on a specific command." >>actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_LOCALE 'xgettext: C extraction with %s' '
+    printf "TILRAUN: C tilraunastrengur %%s" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: A C test string %s" >actual &&
+    test_cmp expect actual
+'
+
+# xgettext from Shell
+test_expect_success GETTEXT_LOCALE 'xgettext: Shell extraction' '
+    printf "TILRAUN: Skeljartilraunastrengur" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: A Shell test string" >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_LOCALE 'xgettext: Shell extraction with $variable' '
+    printf "TILRAUN: Skeljartilraunastrengur með breytunni a var i able" >x-expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" variable="a var i able" eval_gettext "TEST: A Shell test \$variable" >x-actual &&
+    test_cmp x-expect x-actual
+'
+
+# xgettext from Perl
+test_expect_success GETTEXT_LOCALE 'xgettext: Perl extraction' '
+    printf "TILRAUN: Perl tilraunastrengur" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: A Perl test string" >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_LOCALE 'xgettext: Perl extraction with %s' '
+    printf "TILRAUN: Perl tilraunastrengur með breytunni %%s" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: A Perl test variable %s" >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_LOCALE 'sanity: Some gettext("") data for real locale' '
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "" >real-locale &&
+    test -s real-locale
+'
+
+test_done
diff --git a/t/t0200/test.c b/t/t0200/test.c
new file mode 100644
index 000000000..584d45cf3
--- /dev/null
+++ b/t/t0200/test.c
@@ -0,0 +1,23 @@
+/* This is a phony C program that's only here to test xgettext message extraction */
+
+const char help[] =
+	/* TRANSLATORS: This is a test. You don't need to translate it. */
+	N_("See 'git help COMMAND' for more information on a specific command.");
+
+int main(void)
+{
+	/* TRANSLATORS: This is a test. You don't need to translate it. */
+	puts(_("TEST: A C test string"));
+
+	/* TRANSLATORS: This is a test. You don't need to translate it. */
+	printf(_("TEST: A C test string %s"), "variable");
+
+	/* TRANSLATORS: This is a test. You don't need to translate it. */
+	printf(_("TEST: Hello World!"));
+
+	/* TRANSLATORS: This is a test. You don't need to translate it. */
+	printf(_("TEST: Old English Runes"));
+
+	/* TRANSLATORS: This is a test. You don't need to translate it. */
+	printf(_("TEST: ‘single’ and “double” quotes"));
+}
diff --git a/t/t0200/test.perl b/t/t0200/test.perl
new file mode 100644
index 000000000..36fba341b
--- /dev/null
+++ b/t/t0200/test.perl
@@ -0,0 +1,14 @@
+# This is a phony Perl program that's only here to test xgettext
+# message extraction
+
+# so the above comment won't be folded into the next one by xgettext
+1;
+
+# TRANSLATORS: This is a test. You don't need to translate it.
+print __("TEST: A Perl test string");
+
+# TRANSLATORS: This is a test. You don't need to translate it.
+printf __("TEST: A Perl test variable %s"), "moo";
+
+# TRANSLATORS: If you see this, Git has a bug
+print _"TEST: A Perl string xgettext will not get";
diff --git a/t/t0200/test.sh b/t/t0200/test.sh
new file mode 100644
index 000000000..022d607f4
--- /dev/null
+++ b/t/t0200/test.sh
@@ -0,0 +1,14 @@
+# This is a phony Shell program that's only here to test xgettext
+# message extraction
+
+# so the above comment won't be folded into the next one by xgettext
+echo
+
+# TRANSLATORS: This is a test. You don't need to translate it.
+gettext "TEST: A Shell test string"
+
+# TRANSLATORS: This is a test. You don't need to translate it.
+eval_gettext "TEST: A Shell test \$variable"
+
+# TRANSLATORS: If you see this, Git has a bug
+_("TEST: A Shell string xgettext won't get")
diff --git a/t/t0201-gettext-fallbacks.sh b/t/t0201-gettext-fallbacks.sh
index 54d98b9b1..52b1c27c2 100755
--- a/t/t0201-gettext-fallbacks.sh
+++ b/t/t0201-gettext-fallbacks.sh
@@ -5,8 +5,24 @@
 
 test_description='Gettext Shell fallbacks'
 
-. ./test-lib.sh
-. "$GIT_BUILD_DIR"/git-sh-i18n
+GIT_INTERNAL_GETTEXT_TEST_FALLBACKS=YesPlease
+export GIT_INTERNAL_GETTEXT_TEST_FALLBACKS
+
+. ./lib-gettext.sh
+
+test_expect_success "sanity: \$GIT_INTERNAL_GETTEXT_SH_SCHEME is set (to $GIT_INTERNAL_GETTEXT_SH_SCHEME)" '
+    test -n "$GIT_INTERNAL_GETTEXT_SH_SCHEME"
+'
+
+test_expect_success 'sanity: $GIT_INTERNAL_GETTEXT_TEST_FALLBACKS is set' '
+    test -n "$GIT_INTERNAL_GETTEXT_TEST_FALLBACKS"
+'
+
+test_expect_success C_LOCALE_OUTPUT 'sanity: $GIT_INTERNAL_GETTEXT_SH_SCHEME" is fallthrough' '
+    echo fallthrough >expect &&
+    echo $GIT_INTERNAL_GETTEXT_SH_SCHEME >actual &&
+    test_cmp expect actual
+'
 
 test_expect_success 'gettext: our gettext() fallback has pass-through semantics' '
     printf "test" >expect &&
diff --git a/t/t0202-gettext-perl.sh b/t/t0202-gettext-perl.sh
new file mode 100755
index 000000000..428ebb008
--- /dev/null
+++ b/t/t0202-gettext-perl.sh
@@ -0,0 +1,27 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Ævar Arnfjörð Bjarmason
+#
+
+test_description='Perl gettext interface (Git::I18N)'
+
+. ./lib-gettext.sh
+
+if ! test_have_prereq PERL; then
+	skip_all='skipping perl interface tests, perl not available'
+	test_done
+fi
+
+"$PERL_PATH" -MTest::More -e 0 2>/dev/null || {
+	skip_all="Perl Test::More unavailable, skipping test"
+	test_done
+}
+
+# The external test will outputs its own plan
+test_external_has_tap=1
+
+test_external_without_stderr \
+    'Perl Git::I18N API' \
+    "$PERL_PATH" "$TEST_DIRECTORY"/t0202/test.pl
+
+test_done
diff --git a/t/t0202/test.pl b/t/t0202/test.pl
new file mode 100644
index 000000000..2c10cb469
--- /dev/null
+++ b/t/t0202/test.pl
@@ -0,0 +1,110 @@
+#!/usr/bin/perl
+use 5.008;
+use lib (split(/:/, $ENV{GITPERLLIB}));
+use strict;
+use warnings;
+use POSIX qw(:locale_h);
+use Test::More tests => 8;
+use Git::I18N;
+
+my $has_gettext_library = $Git::I18N::__HAS_LIBRARY;
+
+ok(1, "Testing Git::I18N with " .
+	 ($has_gettext_library
+	  ? (defined $Locale::Messages::VERSION
+		 ? "Locale::Messages version $Locale::Messages::VERSION"
+		 # Versions of Locale::Messages before 1.17 didn't have a
+		 # $VERSION variable.
+		 : "Locale::Messages version <1.17")
+	  : "NO Perl gettext library"));
+ok(1, "Git::I18N is located at $INC{'Git/I18N.pm'}");
+
+{
+	my $exports = @Git::I18N::EXPORT;
+	ok($exports, "sanity: Git::I18N has $exports export(s)");
+}
+is_deeply(\@Git::I18N::EXPORT, \@Git::I18N::EXPORT_OK, "sanity: Git::I18N exports everything by default");
+
+# prototypes
+{
+	# Add prototypes here when modifying the public interface to add
+	# more gettext wrapper functions.
+	my %prototypes = (qw(
+		__	$
+	));
+	while (my ($sub, $proto) = each %prototypes) {
+		is(prototype(\&{"Git::I18N::$sub"}), $proto, "sanity: $sub has a $proto prototype");
+	}
+}
+
+# Test basic passthrough in the C locale
+{
+	local $ENV{LANGUAGE} = 'C';
+	local $ENV{LC_ALL}   = 'C';
+	local $ENV{LANG}     = 'C';
+
+	my ($got, $expect) = (('TEST: A Perl test string') x 2);
+
+	is(__($got), $expect, "Passing a string through __() in the C locale works");
+}
+
+# Test a basic message on different locales
+SKIP: {
+	unless ($ENV{GETTEXT_LOCALE}) {
+		# Can't reliably test __() with a non-C locales because the
+		# required locales may not be installed on the system.
+		#
+		# We test for these anyway as part of the shell
+		# tests. Skipping these here will eliminate failures on odd
+		# platforms with incomplete locale data.
+
+		skip "GETTEXT_LOCALE must be set by lib-gettext.sh for exhaustive Git::I18N tests", 2;
+	}
+
+	# The is_IS UTF-8 locale passed from lib-gettext.sh
+	my $is_IS_locale = $ENV{is_IS_locale};
+
+	my $test = sub {
+		my ($got, $expect, $msg, $locale) = @_;
+		# Maybe this system doesn't have the locale we're trying to
+		# test.
+		my $locale_ok = setlocale(LC_ALL, $locale);
+		is(__($got), $expect, "$msg a gettext library + <$locale> locale <$got> turns into <$expect>");
+	};
+
+	my $env_C = sub {
+		$ENV{LANGUAGE} = 'C';
+		$ENV{LC_ALL}   = 'C';
+	};
+
+	my $env_is = sub {
+		$ENV{LANGUAGE} = 'is';
+		$ENV{LC_ALL}   = $is_IS_locale;
+	};
+
+	# Translation's the same as the original
+	my ($got, $expect) = (('TEST: A Perl test string') x 2);
+
+	if ($has_gettext_library) {
+		{
+			local %ENV; $env_C->();
+			$test->($got, $expect, "With", 'C');
+		}
+
+		{
+			my ($got, $expect) = ($got, 'TILRAUN: Perl tilraunastrengur');
+			local %ENV; $env_is->();
+			$test->($got, $expect, "With", $is_IS_locale);
+		}
+	} else {
+		{
+			local %ENV; $env_C->();
+			$test->($got, $expect, "Without", 'C');
+		}
+
+		{
+			local %ENV; $env_is->();
+			$test->($got, $expect, "Without", 'is');
+		}
+	}
+}
diff --git a/t/t0203-gettext-setlocale-sanity.sh b/t/t0203-gettext-setlocale-sanity.sh
new file mode 100755
index 000000000..a21246008
--- /dev/null
+++ b/t/t0203-gettext-setlocale-sanity.sh
@@ -0,0 +1,26 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Ævar Arnfjörð Bjarmason
+#
+
+test_description="The Git C functions aren't broken by setlocale(3)"
+
+. ./lib-gettext.sh
+
+test_expect_success 'git show a ISO-8859-1 commit under C locale' '
+	. "$TEST_DIRECTORY"/t3901-8859-1.txt &&
+	test_commit "iso-c-commit" iso-under-c &&
+	git show >out 2>err &&
+	! test -s err &&
+	grep -q "iso-c-commit" out
+'
+
+test_expect_success GETTEXT_LOCALE 'git show a ISO-8859-1 commit under a UTF-8 locale' '
+	. "$TEST_DIRECTORY"/t3901-8859-1.txt &&
+	test_commit "iso-utf8-commit" iso-under-utf8 &&
+	LANGUAGE=is LC_ALL="$is_IS_locale" git show >out 2>err &&
+	! test -s err &&
+	grep -q "iso-utf8-commit" out
+'
+
+test_done
diff --git a/t/t0204-gettext-reencode-sanity.sh b/t/t0204-gettext-reencode-sanity.sh
new file mode 100755
index 000000000..189af90c0
--- /dev/null
+++ b/t/t0204-gettext-reencode-sanity.sh
@@ -0,0 +1,78 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Ævar Arnfjörð Bjarmason
+#
+
+test_description="Gettext reencoding of our *.po/*.mo files works"
+
+. ./lib-gettext.sh
+
+
+test_expect_success GETTEXT_LOCALE 'gettext: Emitting UTF-8 from our UTF-8 *.mo files / Icelandic' '
+    printf "TILRAUN: Halló Heimur!" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: Hello World!" >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_LOCALE 'gettext: Emitting UTF-8 from our UTF-8 *.mo files / Runes' '
+    printf "TILRAUN: ᚻᛖ ᚳᚹᚫᚦ ᚦᚫᛏ ᚻᛖ ᛒᚢᛞᛖ ᚩᚾ ᚦᚫᛗ ᛚᚪᚾᛞᛖ ᚾᚩᚱᚦᚹᛖᚪᚱᛞᚢᛗ ᚹᛁᚦ ᚦᚪ ᚹᛖᛥᚫ" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: Old English Runes" >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_ISO_LOCALE 'gettext: Emitting ISO-8859-1 from our UTF-8 *.mo files / Icelandic' '
+    printf "TILRAUN: Halló Heimur!" | iconv -f UTF-8 -t ISO8859-1 >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_iso_locale" gettext "TEST: Hello World!" >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_ISO_LOCALE 'gettext: Emitting ISO-8859-1 from our UTF-8 *.mo files / Runes' '
+    LANGUAGE=is LC_ALL="$is_IS_iso_locale" gettext "TEST: Old English Runes" >runes &&
+
+	if grep "^TEST: Old English Runes$" runes
+	then
+		say "Your system can not handle this complexity and returns the string as-is"
+	else
+		# Both Solaris and GNU libintl will return this stream of
+		# question marks, so it is s probably portable enough
+		printf "TILRAUN: ?? ???? ??? ?? ???? ?? ??? ????? ??????????? ??? ?? ????" >runes-expect &&
+		test_cmp runes-expect runes
+	fi
+'
+
+test_expect_success GETTEXT_LOCALE 'gettext: Fetching a UTF-8 msgid -> UTF-8' '
+    printf "TILRAUN: ‚einfaldar‘ og „tvöfaldar“ gæsalappir" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" gettext "TEST: ‘single’ and “double” quotes" >actual &&
+    test_cmp expect actual
+'
+
+# How these quotes get transliterated depends on the gettext implementation:
+#
+#   Debian:  ,einfaldar' og ,,tvöfaldar" [GNU libintl]
+#   FreeBSD: `einfaldar` og "tvöfaldar"  [GNU libintl]
+#   Solaris: ?einfaldar? og ?tvöfaldar?  [Solaris libintl]
+#
+# Just make sure the contents are transliterated, and don't use grep -q
+# so that these differences are emitted under --verbose for curious
+# eyes.
+test_expect_success GETTEXT_ISO_LOCALE 'gettext: Fetching a UTF-8 msgid -> ISO-8859-1' '
+    LANGUAGE=is LC_ALL="$is_IS_iso_locale" gettext "TEST: ‘single’ and “double” quotes" >actual &&
+    grep "einfaldar" actual &&
+    grep "$(echo tvöfaldar | iconv -f UTF-8 -t ISO8859-1)" actual
+'
+
+test_expect_success GETTEXT_LOCALE 'gettext.c: git init UTF-8 -> UTF-8' '
+    printf "Bjó til tóma Git lind" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_locale" git init repo >actual &&
+    test_when_finished "rm -rf repo" &&
+    grep "^$(cat expect) " actual
+'
+
+test_expect_success GETTEXT_ISO_LOCALE 'gettext.c: git init UTF-8 -> ISO-8859-1' '
+    printf "Bjó til tóma Git lind" >expect &&
+    LANGUAGE=is LC_ALL="$is_IS_iso_locale" git init repo >actual &&
+    test_when_finished "rm -rf repo" &&
+    grep "^$(cat expect | iconv -f UTF-8 -t ISO8859-1) " actual
+'
+
+test_done
diff --git a/t/t0205-gettext-poison.sh b/t/t0205-gettext-poison.sh
new file mode 100755
index 000000000..2361590d5
--- /dev/null
+++ b/t/t0205-gettext-poison.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Ævar Arnfjörð Bjarmason
+#
+
+test_description='Gettext Shell poison'
+
+. ./lib-gettext.sh
+
+test_expect_success GETTEXT_POISON "sanity: \$GIT_INTERNAL_GETTEXT_SH_SCHEME is set (to $GIT_INTERNAL_GETTEXT_SH_SCHEME)" '
+    test -n "$GIT_INTERNAL_GETTEXT_SH_SCHEME"
+'
+
+test_expect_success GETTEXT_POISON 'sanity: $GIT_INTERNAL_GETTEXT_SH_SCHEME" is poison' '
+    test "$GIT_INTERNAL_GETTEXT_SH_SCHEME" = "poison"
+'
+
+test_expect_success GETTEXT_POISON 'gettext: our gettext() fallback has poison semantics' '
+    printf "# GETTEXT POISON #" >expect &&
+    gettext "test" >actual &&
+    test_cmp expect actual &&
+    printf "# GETTEXT POISON #" >expect &&
+    gettext "test more words" >actual &&
+    test_cmp expect actual
+'
+
+test_expect_success GETTEXT_POISON 'eval_gettext: our eval_gettext() fallback has poison semantics' '
+    printf "# GETTEXT POISON #" >expect &&
+    eval_gettext "test" >actual &&
+    test_cmp expect actual &&
+    printf "# GETTEXT POISON #" >expect &&
+    eval_gettext "test more words" >actual &&
+    test_cmp expect actual
+'
+
+test_done
diff --git a/t/test-lib.sh b/t/test-lib.sh
index bdd9513b8..9cfabe447 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -44,6 +44,7 @@ export LANG LC_ALL PAGER TERM TZ
 EDITOR=:
 unset VISUAL
 unset EMAIL
+unset LANGUAGE
 unset $(perl -e '
 	my @env = keys %ENV;
 	my $ok = join("|", qw(
@@ -1113,12 +1114,14 @@ esac
 test -z "$NO_PERL" && test_set_prereq PERL
 test -z "$NO_PYTHON" && test_set_prereq PYTHON
 test -n "$USE_LIBPCRE" && test_set_prereq LIBPCRE
+test -z "$NO_GETTEXT" && test_set_prereq GETTEXT
 
 # Can we rely on git's output in the C locale?
 if test -n "$GETTEXT_POISON"
 then
 	GIT_GETTEXT_POISON=YesPlease
 	export GIT_GETTEXT_POISON
+	test_set_prereq GETTEXT_POISON
 else
 	test_set_prereq C_LOCALE_OUTPUT
 fi