[PATCH] git-sh-i18n: detect and avoid broken gettext(1) implementation

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

Even though we can load gettext.sh the gettext(1) and eval_gettext
functions it provides might be completely broken. This reportedly
happens on some Cygwin installations where we can load gettext.sh, but
gettext and eval_gettext both return exit code 127 and no output.

The reason we're trying to load gettext.sh (or the equivalent Solaris
implementation) at all is so we don't have to provide our own fallback
implementation if the OS already has one installed, but because we
didn't test whether it actually worked under GNU gettext we might end
up with broken functions.

Change the detection in git-sh-i18n so that it tests that the output
of "gettext test" produces "test", on Solaris we already test that
"gettext -h" produces "-h", so we were already guarded against the
same sort of failure there.

Reported-by: Alex Riesen <raa.lkml@gmail.com>
---
Here's a minimal patch to git-sh-i18n that should make things work on
Cygwin and any other platforms with broken gettext functions while
also using the OS-provided functions if they work.

I've added a new t0201-gettext-fallbacks-broken-gettext.sh test that
tests this. This required a small change in lib-gettext.sh so I
wouldn't load test-lib.sh twice.

Note that there's already a t0201* test in the repo. Maybe we want to
increment all the gettext test numbers by one to make room for it?

As an aside I'm really not a big fan of having hardcoded numbers in
the test files like this. We don't care about the order of execution
here.

 git-sh-i18n.sh                              |    2 +-
 t/lib-gettext.sh                            |    7 +++++-
 t/t0201-gettext-fallbacks-broken-gettext.sh |   28 +++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100755 t/t0201-gettext-fallbacks-broken-gettext.sh

diff --git a/git-sh-i18n.sh b/git-sh-i18n.sh
index b4575fb..26a57b0 100644
--- a/git-sh-i18n.sh
+++ b/git-sh-i18n.sh
@@ -18,7 +18,7 @@ export TEXTDOMAINDIR
 
 if test -z "$GIT_GETTEXT_POISON"
 then
-	if test -z "$GIT_INTERNAL_GETTEXT_TEST_FALLBACKS" && type gettext.sh >/dev/null 2>&1
+	if test -z "$GIT_INTERNAL_GETTEXT_TEST_FALLBACKS" && type gettext.sh >/dev/null 2>&1 && test "$(gettext test 2>&1)" = "test"
 	then
 		# This is GNU libintl's gettext.sh, we don't need to do anything
 		# else than setting up the environment and loading gettext.sh
diff --git a/t/lib-gettext.sh b/t/lib-gettext.sh
index 0f76f6c..2c5b758 100644
--- a/t/lib-gettext.sh
+++ b/t/lib-gettext.sh
@@ -3,7 +3,12 @@
 # Copyright (c) 2010 Ævar Arnfjörð Bjarmason
 #
 
-. ./test-lib.sh
+if test -z "$TEST_DIRECTORY"
+then
+	# In case the test loaded test-lib.sh by itself to do some tests
+	# prior to loading us.
+	. ./test-lib.sh
+fi
 
 GIT_TEXTDOMAINDIR="$GIT_BUILD_DIR/po/build/locale"
 GIT_PO_PATH="$GIT_BUILD_DIR/po"
diff --git a/t/t0201-gettext-fallbacks-broken-gettext.sh b/t/t0201-gettext-fallbacks-broken-gettext.sh
new file mode 100755
index 0000000..92b95ae
--- /dev/null
+++ b/t/t0201-gettext-fallbacks-broken-gettext.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+#
+# Copyright (c) 2012 Ævar Arnfjörð Bjarmason
+#
+
+test_description='Gettext Shell fallbacks with broken gettext'
+
+. ./test-lib.sh
+
+test_expect_success 'set up a fake broken gettext(1)' '
+	cat >gettext <<-\EOF &&
+	#!/bin/sh
+	exit 1
+	EOF
+	chmod +x gettext &&
+    ! ./gettext
+'
+
+PATH=.:$PATH
+. "$TEST_DIRECTORY"/lib-gettext.sh
+
+test_expect_success C_LOCALE_OUTPUT '$GIT_INTERNAL_GETTEXT_SH_SCHEME" is fallthrough with broken gettext(1)' '
+    echo fallthrough >expect &&
+    echo $GIT_INTERNAL_GETTEXT_SH_SCHEME >actual &&
+    test_cmp expect actual
+'
+
+test_done
-- 
1.7.7.3