git-sh-i18n--envsubst: our own envsubst(1) for eval_gettext()

Add a git-sh-i18n--envsubst program which is a stripped-down version
of the GNU envsubst(1) program that comes with GNU gettext for use in
the eval_gettext() fallback.

We need a C helper program because implementing eval_gettext() purely
in shell turned out to be unworkable. Digging through the Git mailing
list archives will reveal two shell implementations of eval_gettext
that are almost good enough, but fail on an edge case which is tested
for in the tests which are part of this patch.

These are the modifications I made to envsubst.c as I turned it into
sh-i18n--envsubst.c:

 * Added our git-compat-util.h header for xrealloc() and friends.

 * Removed inclusion of gettext-specific headers.

 * Removed most of main() and replaced it with my own. The modified
   version only does option parsing for --variables. That's all it
   needs.

 * Modified error() invocations to use our error() instead of
   error(3).

 * Replaced the gettext XNMALLOC(n, size) macro with just
   xmalloc(n). Since XNMALLOC() only allocated char's.

 * Removed the string_list_destroy function. It's redundant (also in
   the upstream code).

 * Replaced the use of stdbool.h (a C99 header) by doing the following
   replacements on the code:

    * s/bool/unsigned short int/g
    * s/true/1/g
    * s/false/0/g

Reported-by: Johannes Sixt <j.sixt@viscovery.net>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/t/t0201-gettext-fallbacks.sh b/t/t0201-gettext-fallbacks.sh
new file mode 100755
index 0000000000..54d98b9b10
--- /dev/null
+++ b/t/t0201-gettext-fallbacks.sh
@@ -0,0 +1,51 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Ævar Arnfjörð Bjarmason
+#
+
+test_description='Gettext Shell fallbacks'
+
+. ./test-lib.sh
+. "$GIT_BUILD_DIR"/git-sh-i18n
+
+test_expect_success 'gettext: our gettext() fallback has pass-through semantics' '
+    printf "test" >expect &&
+    gettext "test" >actual &&
+    test_i18ncmp expect actual &&
+    printf "test more words" >expect &&
+    gettext "test more words" >actual &&
+    test_i18ncmp expect actual
+'
+
+test_expect_success 'eval_gettext: our eval_gettext() fallback has pass-through semantics' '
+    printf "test" >expect &&
+    eval_gettext "test" >actual &&
+    test_i18ncmp expect actual &&
+    printf "test more words" >expect &&
+    eval_gettext "test more words" >actual &&
+    test_i18ncmp expect actual
+'
+
+test_expect_success 'eval_gettext: our eval_gettext() fallback can interpolate variables' '
+    printf "test YesPlease" >expect &&
+    GIT_INTERNAL_GETTEXT_TEST_FALLBACKS=YesPlease eval_gettext "test \$GIT_INTERNAL_GETTEXT_TEST_FALLBACKS" >actual &&
+    test_i18ncmp expect actual
+'
+
+test_expect_success 'eval_gettext: our eval_gettext() fallback can interpolate variables with spaces' '
+    cmdline="git am" &&
+    export cmdline;
+    printf "When you have resolved this problem run git am --resolved." >expect &&
+    eval_gettext "When you have resolved this problem run \$cmdline --resolved." >actual
+    test_i18ncmp expect actual
+'
+
+test_expect_success 'eval_gettext: our eval_gettext() fallback can interpolate variables with spaces and quotes' '
+    cmdline="git am" &&
+    export cmdline;
+    printf "When you have resolved this problem run \"git am --resolved\"." >expect &&
+    eval_gettext "When you have resolved this problem run \"\$cmdline --resolved\"." >actual
+    test_i18ncmp expect actual
+'
+
+test_done