[PATCH v3 1/6] parse-options: add show_usage_help_and_exit_if_asked()

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 16, 2025, 01:25 UTC
Message-ID: <20250116012524.1557441-2-gitster@pobox.com>
In-Reply-To: <20250116012524.1557441-1-gitster@pobox.com>

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 33bfba0ed4..8a8b934e67 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 d01361ca97..6af4ee148a 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);

-- 
2.48.1-191-gafe818080f