playlist: added support for adding songs not in the music database

Clients which have authenticated via unix socket may add local files
to the MPD playlist, provided that they own the file.

src/command.c

@@ -229,6 +229,10 @@ static int print_playlist_result(struct client *client,
 		command_error(client, ACK_ERROR_SYSTEM, strerror(errno));
 		return -1;
 
+	case PLAYLIST_RESULT_DENIED:
+		command_error(client, ACK_ERROR_NO_EXIST, "Access denied");
+		return -1;
+
 	case PLAYLIST_RESULT_NO_SUCH_SONG:
 		command_error(client, ACK_ERROR_NO_EXIST, "No such song");
 		return -1;
@@ -444,6 +448,12 @@ static int handleAdd(struct client *client,
 	char *path = argv[1];
 	enum playlist_result result;
 
+	if (path[0] == '/') {
+		result = playlist_append_file(path, client_get_uid(client),
+					      NULL);
+		return print_playlist_result(client, result);
+	}
+
 	if (isRemoteUrl(path))
 		return addToPlaylist(path, NULL);
 
@@ -461,7 +471,13 @@ static int handleAddId(struct client *client,
 		       int argc, char *argv[])
 {
 	int added_id;
-	enum playlist_result result = addToPlaylist(argv[1], &added_id);
+	enum playlist_result result;
+
+	if (argv[1][0] == '/')
+		result = playlist_append_file(argv[1], client_get_uid(client),
+					      &added_id);
+	else
+		result = addToPlaylist(argv[1], &added_id);
 
 	if (result != PLAYLIST_RESULT_SUCCESS)
 		return print_playlist_result(client, result);