Merge branch 'sp/help'

* sp/help:
  shell should call the new setup_path() to setup $PATH
  include $PATH in generating list of commands for "help -a"
  use only the $PATH for exec'ing git commands
  list_commands(): simplify code by using chdir()
  "current_exec_path" is a misleading name, use "argv_exec_path"
  remove unused/unneeded "pattern" argument of list_commands
  "git" returns 1; "git help" and "git help -a" return 0

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);

exec_cmd.c

@@ -5,11 +5,11 @@
 
 extern char **environ;
 static const char *builtin_exec_path = GIT_EXEC_PATH;
-static const char *current_exec_path;
+static const char *argv_exec_path;
 
-void git_set_exec_path(const char *exec_path)
+void git_set_argv_exec_path(const char *exec_path)
 {
-	current_exec_path = exec_path;
+	argv_exec_path = exec_path;
 }
 
 
@@ -18,8 +18,8 @@ const char *git_exec_path(void)
 {
 	const char *env;
 
-	if (current_exec_path)
-		return current_exec_path;
+	if (argv_exec_path)
+		return argv_exec_path;
 
 	env = getenv(EXEC_PATH_ENVIRONMENT);
 	if (env && *env) {
@@ -29,85 +29,69 @@ const char *git_exec_path(void)
 	return builtin_exec_path;
 }
 
+static void add_path(struct strbuf *out, const char *path)
+{
+	if (path && *path) {
+		if (is_absolute_path(path))
+			strbuf_addstr(out, path);
+		else
+			strbuf_addstr(out, make_absolute_path(path));
+
+		strbuf_addch(out, ':');
+	}
+}
+
+void setup_path(const char *cmd_path)
+{
+	const char *old_path = getenv("PATH");
+	struct strbuf new_path;
+
+	strbuf_init(&new_path, 0);
+
+	add_path(&new_path, argv_exec_path);
+	add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
+	add_path(&new_path, builtin_exec_path);
+	add_path(&new_path, cmd_path);
+
+	if (old_path)
+		strbuf_addstr(&new_path, old_path);
+	else
+		strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
+
+	setenv("PATH", new_path.buf, 1);
+
+	strbuf_release(&new_path);
+}
 
 int execv_git_cmd(const char **argv)
 {
-	char git_command[PATH_MAX + 1];
-	int i;
-	const char *paths[] = { current_exec_path,
-				getenv(EXEC_PATH_ENVIRONMENT),
-				builtin_exec_path };
-
-	for (i = 0; i < ARRAY_SIZE(paths); ++i) {
-		size_t len;
-		int rc;
-		const char *exec_dir = paths[i];
-		const char *tmp;
-
-		if (!exec_dir || !*exec_dir) continue;
-
-		if (*exec_dir != '/') {
-			if (!getcwd(git_command, sizeof(git_command))) {
-				fprintf(stderr, "git: cannot determine "
-					"current directory: %s\n",
-					strerror(errno));
-				break;
-			}
-			len = strlen(git_command);
-
-			/* Trivial cleanup */
-			while (!prefixcmp(exec_dir, "./")) {
-				exec_dir += 2;
-				while (*exec_dir == '/')
-					exec_dir++;
-			}
-
-			rc = snprintf(git_command + len,
-				      sizeof(git_command) - len, "/%s",
-				      exec_dir);
-			if (rc < 0 || rc >= sizeof(git_command) - len) {
-				fprintf(stderr, "git: command name given "
-					"is too long.\n");
-				break;
-			}
-		} else {
-			if (strlen(exec_dir) + 1 > sizeof(git_command)) {
-				fprintf(stderr, "git: command name given "
-					"is too long.\n");
-				break;
-			}
-			strcpy(git_command, exec_dir);
-		}
-
-		len = strlen(git_command);
-		rc = snprintf(git_command + len, sizeof(git_command) - len,
-			      "/git-%s", argv[0]);
-		if (rc < 0 || rc >= sizeof(git_command) - len) {
-			fprintf(stderr,
-				"git: command name given is too long.\n");
-			break;
-		}
+	struct strbuf cmd;
+	const char *tmp;
 
-		/* argv[0] must be the git command, but the argv array
-		 * belongs to the caller, and my be reused in
-		 * subsequent loop iterations. Save argv[0] and
-		 * restore it on error.
-		 */
+	strbuf_init(&cmd, 0);
+	strbuf_addf(&cmd, "git-%s", argv[0]);
 
-		tmp = argv[0];
-		argv[0] = git_command;
+	/*
+	 * argv[0] must be the git command, but the argv array
+	 * belongs to the caller, and may be reused in
+	 * subsequent loop iterations. Save argv[0] and
+	 * restore it on error.
+	 */
+	tmp = argv[0];
+	argv[0] = cmd.buf;
 
-		trace_argv_printf(argv, -1, "trace: exec:");
+	trace_argv_printf(argv, -1, "trace: exec:");
 
-		/* execve() can only ever return if it fails */
-		execve(git_command, (char **)argv, environ);
+	/* execvp() can only ever return if it fails */
+	execvp(cmd.buf, (char **)argv);
 
-		trace_printf("trace: exec failed: %s\n", strerror(errno));
+	trace_printf("trace: exec failed: %s\n", strerror(errno));
 
-		argv[0] = tmp;
-	}
-	return -1;
+	argv[0] = tmp;
 
+	strbuf_release(&cmd);
+
+	return -1;
 }
 
 

exec_cmd.h

@@ -1,8 +1,9 @@
 #ifndef GIT_EXEC_CMD_H
 #define GIT_EXEC_CMD_H
 
-extern void git_set_exec_path(const char *exec_path);
+extern void git_set_argv_exec_path(const char *exec_path);
 extern const char* git_exec_path(void);
+extern void setup_path(const char *);
 extern int execv_git_cmd(const char **argv); /* NULL terminated */
 extern int execl_git_cmd(const char *cmd, ...);
 

git.c

@@ -6,28 +6,6 @@
 const char git_usage_string[] =
 	"git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";
 
-static void prepend_to_path(const char *dir, int len)
-{
-	const char *old_path = getenv("PATH");
-	char *path;
-	int path_len = len;
-
-	if (!old_path)
-		old_path = "/usr/local/bin:/usr/bin:/bin";
-
-	path_len = len + strlen(old_path) + 1;
-
-	path = xmalloc(path_len + 1);
-
-	memcpy(path, dir, len);
-	path[len] = ':';
-	memcpy(path + len + 1, old_path, path_len - len);
-
-	setenv("PATH", path, 1);
-
-	free(path);
-}
-
 static int handle_options(const char*** argv, int* argc, int* envchanged)
 {
 	int handled = 0;
@@ -51,7 +29,7 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
 		if (!prefixcmp(cmd, "--exec-path")) {
 			cmd += 11;
 			if (*cmd == '=')
-				git_set_exec_path(cmd + 1);
+				git_set_argv_exec_path(cmd + 1);
 			else {
 				puts(git_exec_path());
 				exit(0);
@@ -408,7 +386,7 @@ int main(int argc, const char **argv)
 {
 	const char *cmd = argv[0] ? argv[0] : "git-help";
 	char *slash = strrchr(cmd, '/');
-	const char *exec_path = NULL;
+	const char *cmd_path = NULL;
 	int done_alias = 0;
 
 	/*
@@ -418,10 +396,7 @@ int main(int argc, const char **argv)
 	 */
 	if (slash) {
 		*slash++ = 0;
-		if (*cmd == '/')
-			exec_path = cmd;
-		else
-			exec_path = xstrdup(make_absolute_path(cmd));
+		cmd_path = cmd;
 		cmd = slash;
 	}
 
@@ -450,23 +425,20 @@ 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];
 
 	/*
-	 * We execute external git command via execv_git_cmd(),
-	 * which looks at "--exec-path" option, GIT_EXEC_PATH
-	 * environment, and $(gitexecdir) in Makefile while built,
-	 * in this order.  For scripted commands, we prepend
-	 * the value of the exec_path variable to the PATH.
+	 * We use PATH to find git commands, but we prepend some higher
+	 * precidence paths: the "--exec-path" option, the GIT_EXEC_PATH
+	 * environment, and the $(gitexecdir) from the Makefile at build
+	 * time.
 	 */
-	if (exec_path)
-		prepend_to_path(exec_path, strlen(exec_path));
-	exec_path = git_exec_path();
-	prepend_to_path(exec_path, strlen(exec_path));
+	setup_path(cmd_path);
 
 	while (1) {
 		/* See if it's an internal command */