Implemented oncatenation of split files during -cpx

xorriso/xorriso.1

@@ -1603,7 +1603,7 @@ pseudo-drives or as log files.
 But its alter ego, osirrox, is able to extract file objects
 from ISO images and to create, overwrite, or delete file objects on disk.
 .TP
-\fB\-osirrox\fR "on"|"device_files"|"off"
+\fB\-osirrox\fR ["on"|"device_files"|"off"][:"concat_split_on"|"concat_split_off"]
 Setting "off" disables disk filesystem manipulations. This is the default
 unless the program was started with leafname "osirrox". Elsewise
 the capability to restore files can be enabled explicitly by -osirrox "on".
@@ -1618,6 +1618,11 @@ are ignored during restore operations.
 Due to a bug of previous versions, device files from previous sessions might
 have been altered to major=0, minor=1. So this combination does not get
 restored.
+.br
+"concat_split_on" is default. It enables restoring of split file directories
+as data files if the directory contains a complete  collection of -cut_out
+part files. With "concat_split_off" such directories are handled as any
+other ISO image directory.
 .TP
 \fB\-cpx\fR iso_rr_path [***] disk_path
 Extract single leaf file objects from the ISO image and store them under
@@ -1628,6 +1633,10 @@ created. The extracted files get installed in it with the same leafnames.
 Missing directory components in disk_path will get created, if possible.
 Disk file exclusions are in effect. If this is undesired then perform
 -not_mgt "off" first.
+.br
+Directories are allowed as iso_rr_path only with -osirrox "concat_split_on"
+and only if they actually represent a complete collection of -cut_out split
+file parts.
 .TP
 .B Command compatibility emulations:
 .PP