From b4f7ef8a9006901891611142f56269ee6010bbdb Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 15 Jan 2025 17:25:18 -0800
Subject: [PATCH 1/6] parse-options: add show_usage_help_and_exit_if_asked()

Many commands call usage_with_options() when they are asked to give
the help message, but it incorrectly sends the help text to the
standard error stream.  When the user asked for it with "git cmd -h",
the help message is the primary output from the command, hence we
should send it to the standard output stream.

Introduce a helper function that captures the common pattern

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage_with_options(usage, options);

and replaces it with

	show_usage_help_and_exit_if_asked(argc, argv, usage, options);

to help correct code paths (there are 40 or so of them).

Note that this helper function still exits with status 129, and
t0012 insists on it.  After converting all the mistaken callers of
usage_with_options() to call this new helper, we may want to address
it---the end user is asking us to give the help text, and we are
doing exactly as asked, so there is no reason to exit with non-zero
status.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 parse-options.c | 10 ++++++++++
 parse-options.h |  4 ++++
 2 files changed, 14 insertions(+)

diff --git a/parse-options.c b/parse-options.c
index 33bfba0ed4a0ea..8a8b934e677f46 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -1282,6 +1282,16 @@ void NORETURN usage_with_options(const char * const *usagestr,
 	exit(129);
 }
 
+void show_usage_help_and_exit_if_asked(int ac, const char **av,
+				       const char * const *usagestr,
+				       const struct option *opts)
+{
+	if (ac == 2 && !strcmp(av[1], "-h")) {
+		usage_with_options_internal(NULL, usagestr, opts, 0, 0);
+		exit(129);
+	}
+}
+
 void NORETURN usage_msg_opt(const char *msg,
 		   const char * const *usagestr,
 		   const struct option *options)
diff --git a/parse-options.h b/parse-options.h
index d01361ca97fd72..6af4ee148a0213 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -402,6 +402,10 @@ int parse_options(int argc, const char **argv, const char *prefix,
 NORETURN void usage_with_options(const char * const *usagestr,
 				 const struct option *options);
 
+void show_usage_help_and_exit_if_asked(int ac, const char **av,
+				      const char * const *usage,
+				      const struct option *options);
+
 NORETURN void usage_msg_opt(const char *msg,
 			    const char * const *usagestr,
 			    const struct option *options);

From 796e22a8f828250a7b9ed5dd7b4a0fbb16520ec9 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Wed, 15 Jan 2025 17:25:19 -0800
Subject: [PATCH 2/6] t0012: optionally check that "-h" output goes to stdout

For most commands, "git foo -h" will send the help output to stdout, as
this is what parse-options.c does. But some commands send it to stderr
instead. This is usually because they call usage_with_options(), and
should be switched to show_usage_help_and_exit_if_asked().

Currently t0012 is permissive and allows either behavior. We'd like it
to eventually enforce that help goes to stdout, and teaching it to do so
identifies the commands that need to be changed. But during the
transition period, we don't want to enforce that for most test runs.

So let's introduce a flag that will let most test runs use the
permissive behavior, and people interested in converting commands can
run:

  GIT_TEST_HELP_MUST_BE_STDOUT=1 ./t0012-help.sh

to see the failures. Eventually (when all builtins have been converted)
we'll remove this flag entirely and always check the strict behavior.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t0012-help.sh | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/t/t0012-help.sh b/t/t0012-help.sh
index 1d273d91c2125a..9c7ae9fd36dfd9 100755
--- a/t/t0012-help.sh
+++ b/t/t0012-help.sh
@@ -255,9 +255,16 @@ do
 		(
 			GIT_CEILING_DIRECTORIES=$(pwd) &&
 			export GIT_CEILING_DIRECTORIES &&
-			test_expect_code 129 git -C sub $builtin -h >output 2>&1
+			test_expect_code 129 git -C sub $builtin -h >output 2>err
 		) &&
-		test_grep usage output
+		if test -n "$GIT_TEST_HELP_MUST_BE_STDOUT"
+		then
+			test_must_be_empty err &&
+			test_grep usage output
+		else
+			test_grep usage output ||
+			test_grep usage err
+		fi
 	'
 done <builtins
 

From 7f76ebab1b99b353f066ce2373822612b8657f9a Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 15 Jan 2025 17:25:20 -0800
Subject: [PATCH 3/6] builtins: send usage_with_options() help text to standard
 output

Using the show_usage_help_and_exit_if_asked() helper we introduced
earlier, fix callers of usage_with_options() that want to show the
help text when explicitly asked by the end-user.  The help text now
goes to the standard output stream for them.

The test in t7600 for "git merge -h" may want to be retired, as the
same is covered by t0012 already.  It would be even more true if we
later consider changing the exit status from 129 to 0.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/am.c                | 3 +--
 builtin/branch.c            | 4 ++--
 builtin/checkout--worker.c  | 6 +++---
 builtin/checkout-index.c    | 6 +++---
 builtin/commit-tree.c       | 4 ++--
 builtin/commit.c            | 8 ++++----
 builtin/fsmonitor--daemon.c | 4 ++--
 builtin/gc.c                | 4 ++--
 builtin/ls-files.c          | 4 ++--
 builtin/merge.c             | 4 ++--
 builtin/rebase.c            | 6 +++---
 builtin/update-index.c      | 4 ++--
 t/t7600-merge.sh            | 2 +-
 13 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/builtin/am.c b/builtin/am.c
index 1338b606febdde..0801b556c299a2 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -2427,8 +2427,7 @@ int cmd_am(int argc,
 		OPT_END()
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(usage, options);
+	show_usage_help_and_exit_if_asked(argc, argv, usage, options);
 
 	git_config(git_default_config, NULL);
 
diff --git a/builtin/branch.c b/builtin/branch.c
index 6e7b0cfddbd607..366729a78b7e5b 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -784,8 +784,8 @@ int cmd_branch(int argc,
 	filter.kind = FILTER_REFS_BRANCHES;
 	filter.abbrev = -1;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_branch_usage, options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_branch_usage, options);
 
 	/*
 	 * Try to set sort keys from config. If config does not set any,
diff --git a/builtin/checkout--worker.c b/builtin/checkout--worker.c
index b81002a1dfb4bb..7093d1efd5d68c 100644
--- a/builtin/checkout--worker.c
+++ b/builtin/checkout--worker.c
@@ -128,9 +128,9 @@ int cmd_checkout__worker(int argc,
 		OPT_END()
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(checkout_worker_usage,
-				   checkout_worker_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  checkout_worker_usage,
+					  checkout_worker_options);
 
 	git_config(git_default_config, NULL);
 	argc = parse_options(argc, argv, prefix, checkout_worker_options,
diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index a81501098d9fdb..d928d6b5e30824 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -250,9 +250,9 @@ int cmd_checkout_index(int argc,
 		OPT_END()
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_checkout_index_usage,
-				   builtin_checkout_index_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_checkout_index_usage,
+					  builtin_checkout_index_options);
 	git_config(git_default_config, NULL);
 	prefix_length = prefix ? strlen(prefix) : 0;
 
diff --git a/builtin/commit-tree.c b/builtin/commit-tree.c
index 2ca1a57ebbb230..2efc224d324bee 100644
--- a/builtin/commit-tree.c
+++ b/builtin/commit-tree.c
@@ -119,8 +119,8 @@ int cmd_commit_tree(int argc,
 
 	git_config(git_default_config, NULL);
 
-	if (argc < 2 || !strcmp(argv[1], "-h"))
-		usage_with_options(commit_tree_usage, options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  commit_tree_usage, options);
 
 	argc = parse_options(argc, argv, prefix, options, commit_tree_usage, 0);
 
diff --git a/builtin/commit.c b/builtin/commit.c
index ef5e622c07746f..4268915120564f 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1559,8 +1559,8 @@ struct repository *repo UNUSED)
 		OPT_END(),
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_status_usage, builtin_status_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_status_usage, builtin_status_options);
 
 	prepare_repo_settings(the_repository);
 	the_repository->settings.command_requires_full_index = 0;
@@ -1736,8 +1736,8 @@ int cmd_commit(int argc,
 	struct strbuf err = STRBUF_INIT;
 	int ret = 0;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_commit_usage, builtin_commit_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_commit_usage, builtin_commit_options);
 
 	prepare_repo_settings(the_repository);
 	the_repository->settings.command_requires_full_index = 0;
diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c
index 029dc64d6c70fd..dabf190bbe776c 100644
--- a/builtin/fsmonitor--daemon.c
+++ b/builtin/fsmonitor--daemon.c
@@ -1598,8 +1598,8 @@ int cmd_fsmonitor__daemon(int argc, const char **argv, const char *prefix UNUSED
 		OPT_END()
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_fsmonitor__daemon_usage, options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_fsmonitor__daemon_usage, options);
 
 	die(_("fsmonitor--daemon not supported on this platform"));
 }
diff --git a/builtin/gc.c b/builtin/gc.c
index a9b1c36de27da2..5f831e1f9480f5 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -710,8 +710,8 @@ struct repository *repo UNUSED)
 		OPT_END()
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_gc_usage, builtin_gc_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_gc_usage, builtin_gc_options);
 
 	strvec_pushl(&reflog, "reflog", "expire", "--all", NULL);
 	strvec_pushl(&repack, "repack", "-d", "-l", NULL);
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 15499cd12b6bd5..9efe92b7c0088a 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -644,8 +644,8 @@ int cmd_ls_files(int argc,
 	};
 	int ret = 0;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(ls_files_usage, builtin_ls_files_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  ls_files_usage, builtin_ls_files_options);
 
 	prepare_repo_settings(the_repository);
 	the_repository->settings.command_requires_full_index = 0;
diff --git a/builtin/merge.c b/builtin/merge.c
index 5f67007bbad833..95d798fc89b408 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1300,8 +1300,8 @@ int cmd_merge(int argc,
 	void *branch_to_free;
 	int orig_argc = argc;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_merge_usage, builtin_merge_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_merge_usage, builtin_merge_options);
 
 	prepare_repo_settings(the_repository);
 	the_repository->settings.command_requires_full_index = 0;
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 0498fff3c96d57..cb49323c4457b2 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1223,9 +1223,9 @@ int cmd_rebase(int argc,
 	};
 	int i;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_rebase_usage,
-				   builtin_rebase_options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  builtin_rebase_usage,
+					  builtin_rebase_options);
 
 	prepare_repo_settings(the_repository);
 	the_repository->settings.command_requires_full_index = 0;
diff --git a/builtin/update-index.c b/builtin/update-index.c
index 74bbad9f87d86d..b0e2ad4970ce22 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -1045,8 +1045,8 @@ int cmd_update_index(int argc,
 		OPT_END()
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(update_index_usage, options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  update_index_usage, options);
 
 	git_config(git_default_config, NULL);
 
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index ef54cff4faa8d3..2a8df292196468 100755
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -173,7 +173,7 @@ test_expect_success 'merge -h with invalid index' '
 		cd broken &&
 		git init &&
 		>.git/index &&
-		test_expect_code 129 git merge -h 2>usage
+		test_expect_code 129 git merge -h >usage
 	) &&
 	test_grep "[Uu]sage: git merge" broken/usage
 '

From fda04918a05d8c680b6ab73a6352fc39e7f87caa Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 15 Jan 2025 17:25:21 -0800
Subject: [PATCH 4/6] usage: add show_usage_and_exit_if_asked()

Some commands call usage() when they are asked to give the help
message with "git cmd -h", but this has the same problem as we
fixed with callers of usage_with_options() for the same purpose.

Introduce a helper function that captures the common pattern

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage(usage);

and replaces it with

	show_usage_and_exit_if_asked(argc, argv, usage);

to help correct these code paths.

Note that this helper function still exits with status 129, and
t0012 insists on it.  After converting all the mistaken callers of
usage_with_options() to call this new helper, we may want to address
it---the end user is asking us to give the help text, and we are
doing exactly as asked, so there is no reason to exit with non-zero
status.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-compat-util.h |  2 ++
 usage.c           | 28 +++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/git-compat-util.h b/git-compat-util.h
index e283c46c6fa06e..6edf50bc95da60 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -701,6 +701,8 @@ int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
+void show_usage_and_exit_if_asked(int ac, const char **av, const char *err);
+
 #ifndef NO_OPENSSL
 #ifdef APPLE_COMMON_CRYPTO
 #include "compat/apple-common-crypto.h"
diff --git a/usage.c b/usage.c
index 47709006c15f67..26cd54a5111c9a 100644
--- a/usage.c
+++ b/usage.c
@@ -8,7 +8,7 @@
 #include "gettext.h"
 #include "trace2.h"
 
-static void vreportf(const char *prefix, const char *err, va_list params)
+static void vfdreportf(int fd, const char *prefix, const char *err, va_list params)
 {
 	char msg[4096];
 	char *p, *pend = msg + sizeof(msg);
@@ -32,8 +32,14 @@ static void vreportf(const char *prefix, const char *err, va_list params)
 	}
 
 	*(p++) = '\n'; /* we no longer need a NUL */
-	fflush(stderr);
-	write_in_full(2, msg, p - msg);
+	if (fd == 2)
+		fflush(stderr);
+	write_in_full(fd, msg, p - msg);
+}
+
+static void vreportf(const char *prefix, const char *err, va_list params)
+{
+	vfdreportf(2, prefix, err, params);
 }
 
 static NORETURN void usage_builtin(const char *err, va_list params)
@@ -173,6 +179,22 @@ void NORETURN usage(const char *err)
 	usagef("%s", err);
 }
 
+static void show_usage_and_exit_if_asked_helper(const char *err, ...)
+{
+	va_list params;
+
+	va_start(params, err);
+	vfdreportf(1, _("usage: "), err, params);
+	va_end(params);
+	exit(129);
+}
+
+void show_usage_and_exit_if_asked(int ac, const char **av, const char *err)
+{
+	if (ac == 2 && !strcmp(av[1], "-h"))
+		show_usage_and_exit_if_asked_helper(err);
+}
+
 void NORETURN die(const char *err, ...)
 {
 	va_list params;

From ffbeb8df2dc7f4ff5d9bf0aab94886f07ff00831 Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 15 Jan 2025 17:25:22 -0800
Subject: [PATCH 5/6] oddballs: send usage() help text to standard output

Using the show_usage_and_exit_if_asked() helper we introduced
earlier, fix callers of usage() that want to show the help text when
explicitly asked by the end-user.  The help text now goes to the
standard output stream for them.

The callers in this step are oddballs in that their invocations of
usage() are *not* guarded by

	if (argc == 2 && !strcmp(argv[1], "-h")
		usage(...);

They are (unnecessarily) being clever and do things like

	if (argc != 2 || !strcmp(argv[1], "-h")
		usage(...);

to say "I know I take only one argument, so argc != 2 is always an
error regardless of what is in argv[].  Ah, by the way, even if argc
is 2, "-h" is a request for usage text, so we do the same".  Some
just do not treat "-h" any specially, and let it take the same error
code paths as a parameter error.

Now we cannot do the same, so these callers are rewrittin to do the
show_usage_and_exit_if_asked() first and then handle the usage error
the way they used to.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/credential.c     | 3 ++-
 builtin/unpack-file.c    | 8 ++++++--
 builtin/upload-archive.c | 3 ++-
 builtin/var.c            | 1 +
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/builtin/credential.c b/builtin/credential.c
index 14c8c6608b2fbd..8a8cffecc8e559 100644
--- a/builtin/credential.c
+++ b/builtin/credential.c
@@ -18,7 +18,8 @@ int cmd_credential(int argc,
 
 	git_config(git_default_config, NULL);
 
-	if (argc != 2 || !strcmp(argv[1], "-h"))
+	show_usage_and_exit_if_asked(argc, argv, usage_msg);
+	if (argc != 2)
 		usage(usage_msg);
 	op = argv[1];
 
diff --git a/builtin/unpack-file.c b/builtin/unpack-file.c
index 6da282575391b9..307351af5524dc 100644
--- a/builtin/unpack-file.c
+++ b/builtin/unpack-file.c
@@ -26,6 +26,9 @@ static char *create_temp_file(struct object_id *oid)
 	return path;
 }
 
+static const char usage_msg[] =
+"git unpack-file <blob>";
+
 int cmd_unpack_file(int argc,
 		    const char **argv,
 		    const char *prefix UNUSED,
@@ -33,8 +36,9 @@ int cmd_unpack_file(int argc,
 {
 	struct object_id oid;
 
-	if (argc != 2 || !strcmp(argv[1], "-h"))
-		usage("git unpack-file <blob>");
+	show_usage_and_exit_if_asked(argc, argv, usage_msg);
+	if (argc != 2)
+		usage(usage_msg);
 	if (repo_get_oid(the_repository, argv[1], &oid))
 		die("Not a valid object name %s", argv[1]);
 
diff --git a/builtin/upload-archive.c b/builtin/upload-archive.c
index 9e9343f1213be7..3b282d41e6d6cf 100644
--- a/builtin/upload-archive.c
+++ b/builtin/upload-archive.c
@@ -27,7 +27,8 @@ int cmd_upload_archive_writer(int argc,
 	const char *arg_cmd = "argument ";
 	int ret;
 
-	if (argc != 2 || !strcmp(argv[1], "-h"))
+	show_usage_and_exit_if_asked(argc, argv, upload_archive_usage);
+	if (argc != 2)
 		usage(upload_archive_usage);
 
 	if (!enter_repo(argv[1], 0))
diff --git a/builtin/var.c b/builtin/var.c
index 1449656cc924f8..6a09c1c39a31a6 100644
--- a/builtin/var.c
+++ b/builtin/var.c
@@ -221,6 +221,7 @@ int cmd_var(int argc,
 	const struct git_var *git_var;
 	char *val;
 
+	show_usage_and_exit_if_asked(argc, argv, var_usage);
 	if (argc != 2)
 		usage(var_usage);
 

From 2d4967cc7c6f9140e71bf52d97973b3990c7ca1e Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 15 Jan 2025 17:25:23 -0800
Subject: [PATCH 6/6] builtin: send usage() help text to standard output

Using the show_usage_and_exit_if_asked() helper we introduced
earlier, fix callers of usage() that want to show the help text when
explicitly asked by the end-user.  The help text now goes to the
standard output stream for them.

These are the bog standard "if we got only '-h', then that is a
request for help" callers.  Their

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage(message);

are simply replaced with

	show_usage_and_exit_if_asked(argc, argv, message);

With this, the built-ins tested by t0012 all send their help text to
their standard output stream, so the check in t0012 that was half
tightened earlier is now fully tightened to insist on standard error
stream being empty.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/check-ref-format.c  |  4 ++--
 builtin/diff-files.c        |  3 +--
 builtin/diff-index.c        |  3 +--
 builtin/diff-tree.c         |  3 +--
 builtin/fast-import.c       |  3 +--
 builtin/fetch-pack.c        |  3 +++
 builtin/get-tar-commit-id.c |  4 +++-
 builtin/index-pack.c        |  3 +--
 builtin/mailsplit.c         |  4 ++--
 builtin/merge-index.c       |  7 ++++++-
 builtin/merge-ours.c        |  3 +--
 builtin/merge-recursive.c   |  6 ++++++
 builtin/pack-redundant.c    |  3 +--
 builtin/remote-ext.c        |  2 ++
 builtin/remote-fd.c         |  1 +
 builtin/rev-list.c          |  3 +--
 builtin/rev-parse.c         |  2 ++
 builtin/unpack-objects.c    |  2 ++
 builtin/upload-archive.c    |  3 +--
 t/helper/test-simple-ipc.c  |  4 ++--
 t/t0012-help.sh             | 10 ++--------
 21 files changed, 42 insertions(+), 34 deletions(-)

diff --git a/builtin/check-ref-format.c b/builtin/check-ref-format.c
index cef1ffe3ceb719..acc4366d85b791 100644
--- a/builtin/check-ref-format.c
+++ b/builtin/check-ref-format.c
@@ -64,8 +64,8 @@ int cmd_check_ref_format(int argc,
 
 	BUG_ON_NON_EMPTY_PREFIX(prefix);
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(builtin_check_ref_format_usage);
+	show_usage_and_exit_if_asked(argc, argv,
+				     builtin_check_ref_format_usage);
 
 	if (argc == 3 && !strcmp(argv[1], "--branch"))
 		return check_ref_format_branch(argv[2]);
diff --git a/builtin/diff-files.c b/builtin/diff-files.c
index 604b04bb2c8694..f8816e0d9e6ae3 100644
--- a/builtin/diff-files.c
+++ b/builtin/diff-files.c
@@ -29,8 +29,7 @@ int cmd_diff_files(int argc,
 	int result;
 	unsigned options = 0;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(diff_files_usage);
+	show_usage_and_exit_if_asked(argc, argv, diff_files_usage);
 
 	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
 
diff --git a/builtin/diff-index.c b/builtin/diff-index.c
index ebc824602e02e6..a1759b82918c00 100644
--- a/builtin/diff-index.c
+++ b/builtin/diff-index.c
@@ -26,8 +26,7 @@ int cmd_diff_index(int argc,
 	int i;
 	int result;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(diff_cache_usage);
+	show_usage_and_exit_if_asked(argc, argv, diff_cache_usage);
 
 	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
 
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index 40804e7b48e319..fc7c02655554b5 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -122,8 +122,7 @@ int cmd_diff_tree(int argc,
 	int read_stdin = 0;
 	int merge_base = 0;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(diff_tree_usage);
+	show_usage_and_exit_if_asked(argc, argv, diff_tree_usage);
 
 	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
 
diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index 0f86392761abbe..e1f6bfdc731886 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -3565,8 +3565,7 @@ int cmd_fast_import(int argc,
 {
 	unsigned int i;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(fast_import_usage);
+	show_usage_and_exit_if_asked(argc, argv, fast_import_usage);
 
 	reset_pack_idx_option(&pack_idx_opts);
 	git_pack_config();
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index bed2816c2d4a21..9bd4b29c5b6314 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -176,6 +176,9 @@ int cmd_fetch_pack(int argc,
 			list_objects_filter_set_no_filter(&args.filter_options);
 			continue;
 		}
+
+		if (!strcmp(arg, "-h"))
+			show_usage_and_exit_if_asked(2, &arg - 1, fetch_pack_usage);
 		usage(fetch_pack_usage);
 	}
 	if (deepen_not.nr)
diff --git a/builtin/get-tar-commit-id.c b/builtin/get-tar-commit-id.c
index 6bec0d1854c03e..033a205ba430e4 100644
--- a/builtin/get-tar-commit-id.c
+++ b/builtin/get-tar-commit-id.c
@@ -13,7 +13,7 @@ static const char builtin_get_tar_commit_id_usage[] =
 #define HEADERSIZE (2 * RECORDSIZE)
 
 int cmd_get_tar_commit_id(int argc,
-			  const char **argv UNUSED,
+			  const char **argv,
 			  const char *prefix,
 			  struct repository *repo UNUSED)
 {
@@ -27,6 +27,8 @@ int cmd_get_tar_commit_id(int argc,
 
 	BUG_ON_NON_EMPTY_PREFIX(prefix);
 
+	show_usage_and_exit_if_asked(argc, argv, builtin_get_tar_commit_id_usage);
+
 	if (argc != 1)
 		usage(builtin_get_tar_commit_id_usage);
 
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 0b62b2589f10f9..92ef59fad5a1f7 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1897,8 +1897,7 @@ int cmd_index_pack(int argc,
 	 */
 	fetch_if_missing = 0;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(index_pack_usage);
+	show_usage_and_exit_if_asked(argc, argv, index_pack_usage);
 
 	disable_replace_refs();
 	fsck_options.walk = mark_link;
diff --git a/builtin/mailsplit.c b/builtin/mailsplit.c
index 41dd3047313e6c..9e11bffdfb0cd1 100644
--- a/builtin/mailsplit.c
+++ b/builtin/mailsplit.c
@@ -284,6 +284,8 @@ int cmd_mailsplit(int argc,
 
 	BUG_ON_NON_EMPTY_PREFIX(prefix);
 
+	show_usage_and_exit_if_asked(argc, argv, git_mailsplit_usage);
+
 	for (argp = argv+1; *argp; argp++) {
 		const char *arg = *argp;
 
@@ -297,8 +299,6 @@ int cmd_mailsplit(int argc,
 			continue;
 		} else if ( arg[1] == 'f' ) {
 			nr = strtol(arg+2, NULL, 10);
-		} else if ( arg[1] == 'h' ) {
-			usage(git_mailsplit_usage);
 		} else if ( arg[1] == 'b' && !arg[2] ) {
 			allow_bare = 1;
 		} else if (!strcmp(arg, "--keep-cr")) {
diff --git a/builtin/merge-index.c b/builtin/merge-index.c
index 342699edb77c97..f243a55d3274a4 100644
--- a/builtin/merge-index.c
+++ b/builtin/merge-index.c
@@ -75,6 +75,9 @@ static void merge_all(void)
 	}
 }
 
+static const char usage_string[] =
+"git merge-index [-o] [-q] <merge-program> (-a | [--] [<filename>...])";
+
 int cmd_merge_index(int argc,
 		    const char **argv,
 		    const char *prefix UNUSED,
@@ -87,8 +90,10 @@ int cmd_merge_index(int argc,
 	 */
 	signal(SIGCHLD, SIG_DFL);
 
+	show_usage_and_exit_if_asked(argc, argv, usage_string);
+
 	if (argc < 3)
-		usage("git merge-index [-o] [-q] <merge-program> (-a | [--] [<filename>...])");
+		usage(usage_string);
 
 	repo_read_index(the_repository);
 
diff --git a/builtin/merge-ours.c b/builtin/merge-ours.c
index 3ecd9172f18466..ab78fffb52617f 100644
--- a/builtin/merge-ours.c
+++ b/builtin/merge-ours.c
@@ -23,8 +23,7 @@ int cmd_merge_ours(int argc,
 		   const char *prefix UNUSED,
 		   struct repository *repo UNUSED)
 {
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(builtin_merge_ours_usage);
+	show_usage_and_exit_if_asked(argc, argv, builtin_merge_ours_usage);
 
 	/*
 	 * The contents of the current index becomes the tree we
diff --git a/builtin/merge-recursive.c b/builtin/merge-recursive.c
index 1dd295558b207d..b71c7e1c2f05f6 100644
--- a/builtin/merge-recursive.c
+++ b/builtin/merge-recursive.c
@@ -38,6 +38,12 @@ int cmd_merge_recursive(int argc,
 	if (argv[0] && ends_with(argv[0], "-subtree"))
 		o.subtree_shift = "";
 
+	if (argc == 2 && !strcmp(argv[1], "-h")) {
+		struct strbuf msg = STRBUF_INIT;
+		strbuf_addf(&msg, builtin_merge_recursive_usage, argv[0]);
+		show_usage_and_exit_if_asked(argc, argv, msg.buf);
+	}
+
 	if (argc < 4)
 		usagef(builtin_merge_recursive_usage, argv[0]);
 
diff --git a/builtin/pack-redundant.c b/builtin/pack-redundant.c
index e046575871956b..ce2e1fde8d7160 100644
--- a/builtin/pack-redundant.c
+++ b/builtin/pack-redundant.c
@@ -595,8 +595,7 @@ int cmd_pack_redundant(int argc, const char **argv, const char *prefix UNUSED, s
 	struct strbuf idx_name = STRBUF_INIT;
 	char buf[GIT_MAX_HEXSZ + 2]; /* hex hash + \n + \0 */
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(pack_redundant_usage);
+	show_usage_and_exit_if_asked(argc, argv, pack_redundant_usage);
 
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
diff --git a/builtin/remote-ext.c b/builtin/remote-ext.c
index 33c8ae0fc7d638..f7591e77017341 100644
--- a/builtin/remote-ext.c
+++ b/builtin/remote-ext.c
@@ -202,6 +202,8 @@ int cmd_remote_ext(int argc,
 {
 	BUG_ON_NON_EMPTY_PREFIX(prefix);
 
+	show_usage_and_exit_if_asked(argc, argv, usage_msg);
+
 	if (argc != 3)
 		usage(usage_msg);
 
diff --git a/builtin/remote-fd.c b/builtin/remote-fd.c
index ae896eda57b86d..1a1aa65273ba12 100644
--- a/builtin/remote-fd.c
+++ b/builtin/remote-fd.c
@@ -64,6 +64,7 @@ int cmd_remote_fd(int argc,
 
 	BUG_ON_NON_EMPTY_PREFIX(prefix);
 
+	show_usage_and_exit_if_asked(argc, argv, usage_msg);
 	if (argc != 3)
 		usage(usage_msg);
 
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 3196da7b2d23e3..5a21d57c43c7f0 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -542,8 +542,7 @@ int cmd_rev_list(int argc,
 	const char *show_progress = NULL;
 	int ret = 0;
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(rev_list_usage);
+	show_usage_and_exit_if_asked(argc, argv, rev_list_usage);
 
 	git_config(git_default_config, NULL);
 	repo_init_revisions(the_repository, &revs, prefix);
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 949747a6b6c7f8..f4c2b1b000520c 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -713,6 +713,8 @@ int cmd_rev_parse(int argc,
 	int seen_end_of_options = 0;
 	enum format_type format = FORMAT_DEFAULT;
 
+	show_usage_and_exit_if_asked(argc, argv, builtin_rev_parse_usage);
+
 	if (argc > 1 && !strcmp("--parseopt", argv[1]))
 		return cmd_parseopt(argc - 1, argv + 1, prefix);
 
diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
index 2197d6d9332117..1f1fb8e6824ebf 100644
--- a/builtin/unpack-objects.c
+++ b/builtin/unpack-objects.c
@@ -619,6 +619,8 @@ int cmd_unpack_objects(int argc,
 
 	quiet = !isatty(2);
 
+	show_usage_and_exit_if_asked(argc, argv, unpack_usage);
+
 	for (i = 1 ; i < argc; i++) {
 		const char *arg = argv[i];
 
diff --git a/builtin/upload-archive.c b/builtin/upload-archive.c
index 3b282d41e6d6cf..42d8f671745512 100644
--- a/builtin/upload-archive.c
+++ b/builtin/upload-archive.c
@@ -93,8 +93,7 @@ struct repository *repo UNUSED)
 
 	BUG_ON_NON_EMPTY_PREFIX(prefix);
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage(upload_archive_usage);
+	show_usage_and_exit_if_asked(argc, argv, upload_archive_usage);
 
 	/*
 	 * Set up sideband subprocess.
diff --git a/t/helper/test-simple-ipc.c b/t/helper/test-simple-ipc.c
index fb5927775daef8..d7a41cd0539eb5 100644
--- a/t/helper/test-simple-ipc.c
+++ b/t/helper/test-simple-ipc.c
@@ -612,8 +612,8 @@ int cmd__simple_ipc(int argc, const char **argv)
 	if (argc < 2)
 		usage_with_options(simple_ipc_usage, options);
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(simple_ipc_usage, options);
+	show_usage_help_and_exit_if_asked(argc, argv,
+					  simple_ipc_usage, options);
 
 	if (argc == 2 && !strcmp(argv[1], "SUPPORTS_SIMPLE_IPC"))
 		return 0;
diff --git a/t/t0012-help.sh b/t/t0012-help.sh
index 9c7ae9fd36dfd9..d3a0967e9d0752 100755
--- a/t/t0012-help.sh
+++ b/t/t0012-help.sh
@@ -257,14 +257,8 @@ do
 			export GIT_CEILING_DIRECTORIES &&
 			test_expect_code 129 git -C sub $builtin -h >output 2>err
 		) &&
-		if test -n "$GIT_TEST_HELP_MUST_BE_STDOUT"
-		then
-			test_must_be_empty err &&
-			test_grep usage output
-		else
-			test_grep usage output ||
-			test_grep usage err
-		fi
+		test_must_be_empty err &&
+		test_grep usage output
 	'
 done <builtins