"git" returns 1; "git help" and "git help -a" return 0

Signed-off-by: Scott R Parish <srp@srparish.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin.h

@@ -6,6 +6,7 @@
 extern const char git_version_string[];
 extern const char git_usage_string[];
 
+extern void list_common_cmds_help(void);
 extern void help_unknown_cmd(const char *cmd);
 extern int write_tree(unsigned char *sha1, int missing_ok, const char *prefix);
 extern void prune_packed_objects(int);

git.c

@@ -450,9 +450,10 @@ int main(int argc, const char **argv)
 		if (!prefixcmp(argv[0], "--"))
 			argv[0] += 2;
 	} else {
-		/* Default command: "help" */
-		argv[0] = "help";
-		argc = 1;
+		/* The user didn't specify a command; give them help */
+		printf("usage: %s\n\n", git_usage_string);
+		list_common_cmds_help();
+		exit(1);
 	}
 	cmd = argv[0];
 

help.c

@@ -147,7 +147,7 @@ static void list_commands(const char *exec_path, const char *pattern)
 	putchar('\n');
 }
 
-static void list_common_cmds_help(void)
+void list_common_cmds_help(void)
 {
 	int i, longest = 0;
 
@@ -203,14 +203,14 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 	if (!help_cmd) {
 		printf("usage: %s\n\n", git_usage_string);
 		list_common_cmds_help();
-		exit(1);
+		exit(0);
 	}
 
 	else if (!strcmp(help_cmd, "--all") || !strcmp(help_cmd, "-a")) {
 		printf("usage: %s\n\n", git_usage_string);
 		if(exec_path)
 			list_commands(exec_path, "git-*");
-		exit(1);
+		exit(0);
 	}
 
 	else