tests: make GIT_TEST_GETTEXT_POISON a boolean

Change the GIT_TEST_GETTEXT_POISON variable from being "non-empty?" to
being a more standard boolean variable.

Since it needed to be checked in both C code and shellscript (via test
-n) it was one of the remaining shellscript-like variables. Now that
we have "env--helper" we can change that.

There's a couple of tricky edge cases that arise because we're using
git_env_bool() early, and the config-reading "env--helper".

If GIT_TEST_GETTEXT_POISON is set to an invalid value die_bad_number()
will die, but to do so it would usually call gettext(). Let's detect
the special case of GIT_TEST_GETTEXT_POISON and always emit that
message in the C locale, lest we infinitely loop.

As seen in the updated tests in t0017-env-helper.sh there's also a
caveat related to "env--helper" needing to read the config for trace2
purposes.

Since the C_LOCALE_OUTPUT prerequisite is lazy and relies on
"env--helper" we could get invalid results if we failed to read the
config (e.g. because we'd loop on includes) when combined with
e.g. "test_i18ngrep" wanting to check with "env--helper" if
GIT_TEST_GETTEXT_POISON was true or not.

I'm crossing my fingers and hoping that a test similar to the one I
removed in the earlier "config tests: simplify include cycle test"
change in this series won't happen again, and testing for this
explicitly in "env--helper"'s own tests.

This change breaks existing uses of
e.g. GIT_TEST_GETTEXT_POISON=YesPlease, which we've documented in
po/README and other places. As noted in [1] we might want to consider
also accepting "YesPlease" in "env--helper" as a special-case.

But as the lack of uproar over 6cdccfce1e ("i18n: make GETTEXT_POISON
a runtime option", 2018-11-08) demonstrates the audience for this
option is a really narrow set of git developers, who shouldn't have
much trouble modifying their test scripts, so I think it's better to
deal with that minor headache now and make all the relevant GIT_TEST_*
variables boolean in the same way than carry the "YesPlease"
special-case forward.

1. https://public-inbox.org/git/xmqqtvckm3h8.fsf@gitster-ct.c.googlers.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ci/lib.sh

@@ -184,7 +184,7 @@ osx-clang|osx-gcc)
 	export GIT_SKIP_TESTS="t9810 t9816"
 	;;
 GIT_TEST_GETTEXT_POISON)
-	export GIT_TEST_GETTEXT_POISON=YesPlease
+	export GIT_TEST_GETTEXT_POISON=true
 	;;
 esac
 

config.c

@@ -956,6 +956,15 @@ static void die_bad_number(const char *name, const char *value)
 	if (!value)
 		value = "";
 
+	if (!strcmp(name, "GIT_TEST_GETTEXT_POISON"))
+		/*
+		 * We explicitly *don't* use _() here since it would
+		 * cause an infinite loop with _() needing to call
+		 * use_gettext_poison(). This is why marked up
+		 * translations with N_() above.
+		 */
+		die(bad_numeric, value, name, error_type);
+
 	if (!(cf && cf->name))
 		die(_(bad_numeric), value, name, _(error_type));
 

gettext.c

@@ -50,10 +50,8 @@ const char *get_preferred_languages(void)
 int use_gettext_poison(void)
 {
 	static int poison_requested = -1;
-	if (poison_requested == -1) {
-		const char *v = getenv("GIT_TEST_GETTEXT_POISON");
-		poison_requested = v && strlen(v) ? 1 : 0;
-	}
+	if (poison_requested == -1)
+		poison_requested = git_env_bool("GIT_TEST_GETTEXT_POISON", 0);
 	return poison_requested;
 }
 

git-sh-i18n.sh

@@ -17,7 +17,9 @@ export TEXTDOMAINDIR
 
 # First decide what scheme to use...
 GIT_INTERNAL_GETTEXT_SH_SCHEME=fallthrough
-if test -n "$GIT_TEST_GETTEXT_POISON"
+if test -n "$GIT_TEST_GETTEXT_POISON" &&
+	    git env--helper --type=bool --default=0 --exit-code \
+		GIT_TEST_GETTEXT_POISON
 then
 	GIT_INTERNAL_GETTEXT_SH_SCHEME=poison
 elif test -n "@@USE_GETTEXT_SCHEME@@"

po/README

@@ -293,7 +293,7 @@ To smoke out issues like these, Git tested with a translation mode that
 emits gibberish on every call to gettext. To use it run the test suite
 with it, e.g.:
 
-    cd t && GIT_TEST_GETTEXT_POISON=YesPlease prove -j 9 ./t[0-9]*.sh
+    cd t && GIT_TEST_GETTEXT_POISON=true prove -j 9 ./t[0-9]*.sh
 
 If tests break with it you should inspect them manually and see if
 what you're translating is sane, i.e. that you're not translating

t/README

@@ -343,8 +343,8 @@ whether this mode is active, and e.g. skip some tests that are hard to
 refactor to deal with it. The "SYMLINKS" prerequisite is currently
 excluded as so much relies on it, but this might change in the future.
 
-GIT_TEST_GETTEXT_POISON=<non-empty?> turns all strings marked for
-translation into gibberish if non-empty (think "test -n"). Used for
+GIT_TEST_GETTEXT_POISON=<boolean> turns all strings marked for
+translation into gibberish if true. Used for
 spotting those tests that need to be marked with a C_LOCALE_OUTPUT
 prerequisite when adding more strings for translation. See "Testing
 marked strings" in po/README for details.

t/t0017-env-helper.sh

@@ -80,4 +80,20 @@ test_expect_success 'env--helper --type=ulong' '
 	test_must_be_empty actual.err
 '
 
+test_expect_success 'env--helper reads config thanks to trace2' '
+	mkdir home &&
+	git config -f home/.gitconfig include.path cycle &&
+	git config -f home/cycle include.path .gitconfig &&
+
+	test_must_fail \
+		env HOME="$(pwd)/home" GIT_TEST_GETTEXT_POISON=false \
+		git config -l 2>err &&
+	grep "exceeded maximum include depth" err &&
+
+	test_must_fail \
+		env HOME="$(pwd)/home" GIT_TEST_GETTEXT_POISON=true \
+		git -C cycle env--helper --type=bool --default=0 --exit-code GIT_TEST_GETTEXT_POISON 2>err &&
+	grep "# GETTEXT POISON #" err
+'
+
 test_done

t/t0205-gettext-poison.sh

@@ -5,7 +5,7 @@
 
 test_description='Gettext Shell poison'
 
-GIT_TEST_GETTEXT_POISON=YesPlease
+GIT_TEST_GETTEXT_POISON=true
 export GIT_TEST_GETTEXT_POISON
 . ./lib-gettext.sh
 
@@ -31,4 +31,9 @@ test_expect_success 'eval_gettext: our eval_gettext() fallback has poison semant
     test_cmp expect actual
 '
 
+test_expect_success "gettext: invalid GIT_TEST_GETTEXT_POISON value doesn't infinitely loop" "
+	test_must_fail env GIT_TEST_GETTEXT_POISON=xyz git version 2>error &&
+	grep \"fatal: bad numeric config value 'xyz' for 'GIT_TEST_GETTEXT_POISON': invalid unit\" error
+"
+
 test_done

t/t1305-config-include.sh

@@ -314,7 +314,7 @@ test_expect_success 'include cycles are detected' '
 	git -C cycle config include.path cycle &&
 	git config -f cycle/cycle include.path config &&
 	test_must_fail \
-		env GIT_TEST_GETTEXT_POISON= \
+		env GIT_TEST_GETTEXT_POISON=false \
 		git -C cycle config --get-all test.value 2>stderr &&
 	grep "exceeded maximum include depth" stderr
 '

t/t7201-co.sh

@@ -249,7 +249,7 @@ test_expect_success 'checkout to detach HEAD (with advice declined)' '
 test_expect_success 'checkout to detach HEAD' '
 	git config advice.detachedHead true &&
 	git checkout -f renamer && git clean -f &&
-	GIT_TEST_GETTEXT_POISON= git checkout renamer^ 2>messages &&
+	GIT_TEST_GETTEXT_POISON=false git checkout renamer^ 2>messages &&
 	grep "HEAD is now at 7329388" messages &&
 	test_line_count -gt 1 messages &&
 	H=$(git rev-parse --verify HEAD) &&

t/t9902-completion.sh

@@ -1706,7 +1706,7 @@ test_expect_success 'sourcing the completion script clears cached commands' '
 '
 
 test_expect_success 'sourcing the completion script clears cached merge strategies' '
-	GIT_TEST_GETTEXT_POISON= &&
+	GIT_TEST_GETTEXT_POISON=false &&
 	__git_compute_merge_strategies &&
 	verbose test -n "$__git_merge_strategies" &&
 	. "$GIT_BUILD_DIR/contrib/completion/git-completion.bash" &&

t/test-lib.sh

@@ -1443,11 +1443,9 @@ then
 	unset GIT_TEST_GETTEXT_POISON_ORIG
 fi
 
-# Can we rely on git's output in the C locale?
-if test -z "$GIT_TEST_GETTEXT_POISON"
-then
-	test_set_prereq C_LOCALE_OUTPUT
-fi
+test_lazy_prereq C_LOCALE_OUTPUT '
+	! git env--helper --type=bool --default=0 --exit-code GIT_TEST_GETTEXT_POISON
+'
 
 if test -z "$GIT_TEST_CHECK_CACHE_TREE"
 then