Merge branch 'nd/fix-directory-attrs-off-by-one' into maint

Merge branch 'nd/fix-directory-attrs-off-by-one' into maint

The attribute mechanism didn't allow limiting attributes to be
applied to only a single directory itself with "path/" like the
exclude mechanism does.  The initial implementation of this that was
merged to 'maint' and 1.8.1.1 had severe performance degradations.

* nd/fix-directory-attrs-off-by-one:
  attr: avoid calling find_basename() twice per path
  attr: fix off-by-one directory component length calculation