Every kind of entry that holds a path, from its parent's three listings.
CUBE lets a folder and a file share one path, and that is a hazard: a
folder made over a file, then deleted, takes the file's record with it
and every listing of the parent fails (CUBE #732, mise #462). Writers ask
this first and refuse a path something else holds.
The kinds holding it (none, one, or more than one), or Err when
the parent could not be read (the reason stacked): a probe that cannot
answer counts the path as taken.
Every kind of entry that holds a path, from its parent's three listings.
CUBE lets a folder and a file share one path, and that is a hazard: a folder made over a file, then deleted, takes the file's record with it and every listing of the parent fails (CUBE #732, mise #462). Writers ask this first and refuse a path something else holds.