Merge branch 'jk/consistent-h'

"git $cmd -h" for builtin commands calls the implementation of the
command (i.e. cmd_$cmd() function) without doing any repository
set-up, and the commands that expect RUN_SETUP is done by the Git
potty needs to be prepared to show the help text without barfing.

* jk/consistent-h:
  t0012: test "-h" with builtins
  git: add hidden --list-builtins option
  version: convert to parse-options
  diff- and log- family: handle "git cmd -h" early
  submodule--helper: show usage for "-h"
  remote-{ext,fd}: print usage message on invalid arguments
  upload-archive: handle "-h" option early
  credential: handle invalid arguments earlier

builtin/credential.c

@@ -10,9 +10,9 @@ int cmd_credential(int argc, const char **argv, const char *prefix)
 	const char *op;
 	struct credential c = CREDENTIAL_INIT;
 
-	op = argv[1];
-	if (!op)
+	if (argc != 2 || !strcmp(argv[1], "-h"))
 		usage(usage_msg);
+	op = argv[1];
 
 	if (credential_read(&c, stdin) < 0)
 		die("unable to read credential from stdin");

builtin/diff-files.c

@@ -20,6 +20,9 @@ int cmd_diff_files(int argc, const char **argv, const char *prefix)
 	int result;
 	unsigned options = 0;
 
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage(diff_files_usage);
+
 	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
 	init_revisions(&rev, prefix);
 	gitmodules_config();

builtin/diff-index.c

@@ -17,6 +17,9 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
 	int i;
 	int result;
 
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage(diff_cache_usage);
+
 	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
 	init_revisions(&rev, prefix);
 	gitmodules_config();

builtin/diff-tree.c

@@ -104,6 +104,9 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 	struct setup_revision_opt s_r_opt;
 	int read_stdin = 0;
 
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage(diff_tree_usage);
+
 	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
 	init_revisions(opt, prefix);
 	gitmodules_config();

builtin/remote-ext.c

@@ -3,6 +3,9 @@
 #include "run-command.h"
 #include "pkt-line.h"
 
+static const char usage_msg[] =
+	"git remote-ext <remote> <url>";
+
 /*
  * URL syntax:
  *	'command [arg1 [arg2 [...]]]'	Invoke command with given arguments.
@@ -193,7 +196,7 @@ static int command_loop(const char *child)
 int cmd_remote_ext(int argc, const char **argv, const char *prefix)
 {
 	if (argc != 3)
-		die("Expected two arguments");
+		usage(usage_msg);
 
 	return command_loop(argv[2]);
 }

builtin/remote-fd.c

@@ -1,6 +1,9 @@
 #include "builtin.h"
 #include "transport.h"
 
+static const char usage_msg[] =
+	"git remote-fd <remote> <url>";
+
 /*
  * URL syntax:
  *	'fd::<inoutfd>[/<anything>]'		Read/write socket pair
@@ -57,7 +60,7 @@ int cmd_remote_fd(int argc, const char **argv, const char *prefix)
 	char *end;
 
 	if (argc != 3)
-		die("Expected two arguments");
+		usage(usage_msg);
 
 	input_fd = (int)strtoul(argv[2], &end, 10);
 

builtin/rev-list.c

@@ -277,6 +277,9 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	int use_bitmap_index = 0;
 	const char *show_progress = NULL;
 
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage(rev_list_usage);
+
 	git_config(git_default_config, NULL);
 	init_revisions(&revs, prefix);
 	revs.abbrev = DEFAULT_ABBREV;

builtin/submodule--helper.c

@@ -1221,9 +1221,8 @@ static struct cmd_struct commands[] = {
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
 {
 	int i;
-	if (argc < 2)
-		die(_("submodule--helper subcommand must be "
-		      "called with a subcommand"));
+	if (argc < 2 || !strcmp(argv[1], "-h"))
+		usage("git submodule--helper <command>");
 
 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
 		if (!strcmp(argv[1], commands[i].cmd)) {

builtin/upload-archive.c

@@ -22,7 +22,7 @@ int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix)
 	struct argv_array sent_argv = ARGV_ARRAY_INIT;
 	const char *arg_cmd = "argument ";
 
-	if (argc != 2)
+	if (argc != 2 || !strcmp(argv[1], "-h"))
 		usage(upload_archive_usage);
 
 	if (!enter_repo(argv[1], 0))
@@ -76,6 +76,9 @@ int cmd_upload_archive(int argc, const char **argv, const char *prefix)
 {
 	struct child_process writer = { argv };
 
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage(upload_archive_usage);
+
 	/*
 	 * Set up sideband subprocess.
 	 *

git.c

@@ -26,6 +26,8 @@ static const char *env_names[] = {
 static char *orig_env[4];
 static int save_restore_env_balance;
 
+static void list_builtins(void);
+
 static void save_env_before_alias(void)
 {
 	int i;
@@ -232,6 +234,9 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			}
 			(*argv)++;
 			(*argc)--;
+		} else if (!strcmp(cmd, "--list-builtins")) {
+			list_builtins();
+			exit(0);
 		} else {
 			fprintf(stderr, "Unknown option: %s\n", cmd);
 			usage(git_usage_string);
@@ -529,6 +534,13 @@ int is_builtin(const char *s)
 	return !!get_builtin(s);
 }
 
+static void list_builtins(void)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(commands); i++)
+		printf("%s\n", commands[i].cmd);
+}
+
 #ifdef STRIP_EXTENSION
 static void strip_extension(const char **argv)
 {

help.c

@@ -9,6 +9,7 @@
 #include "column.h"
 #include "version.h"
 #include "refs.h"
+#include "parse-options.h"
 
 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 {
@@ -383,16 +384,30 @@ const char *help_unknown_cmd(const char *cmd)
 
 int cmd_version(int argc, const char **argv, const char *prefix)
 {
+	int build_options = 0;
+	const char * const usage[] = {
+		N_("git version [<options>]"),
+		NULL
+	};
+	struct option options[] = {
+		OPT_BOOL(0, "build-options", &build_options,
+			 "also print build options"),
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, prefix, options, usage, 0);
+
 	/*
 	 * The format of this string should be kept stable for compatibility
 	 * with external projects that rely on the output of "git version".
+	 *
+	 * Always show the version, even if other options are given.
 	 */
 	printf("git version %s\n", git_version_string);
-	while (*++argv) {
-		if (!strcmp(*argv, "--build-options")) {
-			printf("sizeof-long: %d\n", (int)sizeof(long));
-			/* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
-		}
+
+	if (build_options) {
+		printf("sizeof-long: %d\n", (int)sizeof(long));
+		/* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 	}
 	return 0;
 }

t/t0012-help.sh

@@ -49,4 +49,16 @@ test_expect_success "--help does not work for guides" "
 	test_i18ncmp expect actual
 "
 
+test_expect_success 'generate builtin list' '
+	git --list-builtins >builtins
+'
+
+while read builtin
+do
+	test_expect_success "$builtin can handle -h" '
+		test_expect_code 129 git $builtin -h >output 2>&1 &&
+		test_i18ngrep usage output
+	'
+done <builtins
+
 test_done