patch"git help -a" should search all exec_paths and PATH

exec_cmd.c, exec_cmd.h, git.c, help.c

diff --git a/exec_cmd.c b/exec_cmd.c
index 374ffc9..2c787a4 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -5,21 +5,35 @@
 
 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;
 }
 
+const char *git_argv_exec_path(void)
+{
+	return argv_exec_path;
+}
+
+const char *git_builtin_exec_path(void)
+{
+	return builtin_exec_path;
+}
+
+const char *git_env_exec_path(void)
+{
+	return getenv(EXEC_PATH_ENVIRONMENT); 
+}
 
 /* Returns the highest-priority, location to look for git programs. */
 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) {
@@ -34,7 +48,7 @@ int execv_git_cmd(const char **argv)
 {
 	char git_command[PATH_MAX + 1];
 	int i;
-	const char *paths[] = { current_exec_path,
+	const char *paths[] = { argv_exec_path,
 				getenv(EXEC_PATH_ENVIRONMENT),
 				builtin_exec_path,
 				"" };
diff --git a/exec_cmd.h b/exec_cmd.h
index 849a839..315fe83 100644
--- a/exec_cmd.h
+++ b/exec_cmd.h
@@ -3,6 +3,9 @@
 
 extern void git_set_exec_path(const char *exec_path);
 extern const char* git_exec_path(void);
+extern const char* git_argv_exec_path(void);
+extern const char* git_builtin_exec_path(void);
+extern const char* git_env_exec_path(void);
 extern int execv_git_cmd(const char **argv); /* NULL terminated */
 extern int execl_git_cmd(const char *cmd, ...);
 
diff --git a/git.c b/git.c
index 853e66c..b67fb17 100644
--- a/git.c
+++ b/git.c
@@ -51,7 +51,7 @@ 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);
diff --git a/help.c b/help.c
index b0d2dd4..85b2853 100644
--- a/help.c
+++ b/help.c
@@ -93,37 +93,27 @@ static void pretty_print_string_list(struct cmdname **cmdname, int longest)
 	}
 }
 
-static void list_commands(const char *exec_path, const char *pattern)
+static unsigned int list_commands_in_dir(const char *dir, const char *prefix)
 {
 	unsigned int longest = 0;
-	char path[PATH_MAX];
-	int dirlen;
-	DIR *dir = opendir(exec_path);
+	int start_dir = open(".", O_RDONLY, 0);
+	DIR *dirp = opendir(dir);
 	struct dirent *de;
 
-	if (!dir) {
-		fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
-		exit(1);
+	if (!dirp || chdir(dir)) {
+		fchdir(start_dir);
+		close(start_dir);
+		return 0;
 	}
 
-	dirlen = strlen(exec_path);
-	if (PATH_MAX - 20 < dirlen) {
-		fprintf(stderr, "git: insanely long exec-path '%s'\n",
-			exec_path);
-		exit(1);
-	}
-
-	memcpy(path, exec_path, dirlen);
-	path[dirlen++] = '/';
-
-	while ((de = readdir(dir)) != NULL) {
+	while ((de = readdir(dirp)) != NULL) {
 		struct stat st;
 		int entlen;
-
-		if (prefixcmp(de->d_name, "git-"))
+			
+		if (prefixcmp(de->d_name, prefix))
 			continue;
-		strcpy(path+dirlen, de->d_name);
-		if (stat(path, &st) || /* stat, not lstat */
+
+		if (stat(de->d_name, &st) || /* stat, not lstat */
 		    !S_ISREG(st.st_mode) ||
 		    !(st.st_mode & S_IXUSR))
 			continue;
@@ -137,12 +127,67 @@ static void list_commands(const char *exec_path, const char *pattern)
 
 		add_cmdname(de->d_name + 4, entlen-4);
 	}
-	closedir(dir);
 
-	printf("git commands available in '%s'\n", exec_path);
-	printf("----------------------------");
-	mput_char('-', strlen(exec_path));
-	putchar('\n');
+	closedir(dirp);
+	fchdir(start_dir);
+	close(start_dir);
+
+	return longest;
+}
+
+static unsigned int list_commands_in_PATH(const char *prefix)
+{
+	unsigned int longest = 0;
+	unsigned int len;
+	const char *env_path = getenv("PATH");
+	char *paths, *path, *colon;
+       
+	if (!env_path)
+		return longest;
+
+	path = paths = xstrdup(env_path);
+
+	while ((char *)1 != path) {
+		if ((colon = strchr(path, ':')))
+			*colon = 0;
+
+		len = list_commands_in_dir(path, prefix);
+		longest = MAX(longest, len);
+
+		path = colon + 1;
+	}
+
+	free(paths);
+	return longest;
+}
+
+static void list_commands(const char *prefix)
+{
+	unsigned int longest = 0;
+	unsigned int len;
+	const char *paths[] = { git_argv_exec_path(),
+				git_env_exec_path(),
+				git_builtin_exec_path(),
+				"" };
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(paths); i++) {
+		if (!paths[i])
+			continue;
+
+		if (!*paths[i]) {
+			/* try PATH */
+			len = list_commands_in_PATH(prefix);
+			longest = MAX(longest, len);
+		}
+		else {
+			len = list_commands_in_dir(paths[i], prefix);
+			longest = MAX(longest, len);
+		}
+	}
+
+	printf("available git commands\n");
+	printf("----------------------\n");
 	pretty_print_string_list(cmdname, longest - 4);
 	putchar('\n');
 }
@@ -158,7 +203,7 @@ static void list_common_cmds_help(void)
 
 	puts("The most commonly used git commands are:");
 	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
-		printf("   %s   ", common_cmds[i].name);
+		printf("   %s	", common_cmds[i].name);
 		mput_char(' ', longest - strlen(common_cmds[i].name));
 		puts(common_cmds[i].help);
 	}
@@ -210,7 +255,7 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 	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-*");
+			list_commands("git-");
 		exit(0);
 	}