To create a search index, URLs in the JavaHelp map file (.jhm) must point to files in a subdirectory of the directory where the helpset file is located; the default subdirectory is help\html. See §20.3.6.1 Understanding the JavaHelp / Oracle Help directory structure.
Note: Oracle Help uses a map file only for ALinks and for CSH links; if your Oracle Help project does not include either of those features, there is no map file.
To provide a prefix that points map-file URLs to the correct directory:
[JavaHelpOptions] or [OracleHelpOptions]
; MapFilePrefix = prefix to insert at start of map file URLs
MapFilePrefix = html/
The directory designated by HTMLSubdir (see §20.3.6.2 Letting DITA2Go set up the directory structure and copy files) is the default setting for MapFilePrefix, with “/” added. Use a forward slash, not a backslash, at the end of the prefix; URLs require forward slashes.
MapFilePrefix fixes URLs in the map file, but does not actually move any of the referenced files; see §20.3.6.2 Letting DITA2Go set up the directory structure and copy files.