docs: def prepend_root_dir(opts, path_options):
      '''
      Prepends the options that represent filesystem paths with value of the
      'root_dir' option.
      '''
      root_dir = os.path.abspath(opts['root_dir'])
      def_root_dir = salt.syspaths.ROOT_DIR.rstrip(os.sep)
      for path_option in path_options:
          if path_option in opts:
              path = opts[path_option]
              tmp_path_def_root_dir = None
              tmp_path_root_dir = None
              # When running testsuite, salt.syspaths.ROOT_DIR is often empty
              if path == def_root_dir or path.startswith(def_root_dir + os.sep):
                  # Remove the default root dir prefix
                  tmp_path_def_root_dir = path[len(def_root_dir):]
              if root_dir and (path == root_dir or
                               path.startswith(root_dir + os.sep)):
                  # Remove the root dir prefix
                  tmp_path_root_dir = path[len(root_dir):]
              if tmp_path_def_root_dir and not tmp_path_root_dir:
                  # Just the default root dir matched
                  path = tmp_path_def_root_dir
              elif tmp_path_root_dir and not tmp_path_def_root_dir:
                  # Just the root dir matched
                  path = tmp_path_root_dir
              elif tmp_path_def_root_dir and tmp_path_root_dir:
                  # In this case both the default root dir and the override root
                  # dir matched; this means that either
                  # def_root_dir is a substring of root_dir or vice versa
                  # We must choose the most specific path
                  if def_root_dir in root_dir:
                      path = tmp_path_root_dir
                  else:
                      path = tmp_path_def_root_dir
              elif salt.utils.platform.is_windows() and not os.path.splitdrive(path)[0]:
                  # In windows, os.path.isabs resolves '/' to 'C:\\' or whatever
                  # the root drive is.  This elif prevents the next from being
                  # hit, so that the root_dir is prefixed in cases where the
                  # drive is not prefixed on a config option
                  pass
              elif os.path.isabs(path):
                  # Absolute path (not default or overridden root_dir)
                  # No prepending required
                  continue
              # Prepending the root dir
              opts[path_option] = salt.utils.path.join(root_dir, path)