; Fix documentation of 'file-parent-directory'

* doc/lispref/files.texi (Directory Names):
* lisp/files.el (file-parent-directory): Improve wording of the
documentation of 'file-parent-directory'.  (Bug#56355)

1 files changed, 6 insertions, 3 deletions

diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index ee4e1ec4d96..986fb22c75b 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -2446,9 +2446,12 @@ because it recognizes abbreviations even as part of the name.
 @end defun
 
 @defun file-parent-directory filename
-This function returns the parent directory of @var{filename}.  If
-@var{filename} is at the top level, return @code{nil}.  @var{filename}
-can be relative to @code{default-directory}.
+This function returns the directory name of the parent directory of
+@var{filename}.  If @var{filename} is at the root directory of the
+filesystem, it returns @code{nil}.  A relative @var{filename} is
+assumed to be relative to @code{default-directory}, and the return
+value will also be relative in that case.  If the return value is
+non-@code{nil}, it ends in a slash.
 @end defun
 
 @node File Name Expansion