Extend directory-append to take an arbitrary number of components

* doc/lispref/files.texi (Directory Names): Document it.
* lisp/emacs-lisp/shortdoc.el (file-name): Add new example.

* src/fileio.c (Fdirectory_append): Change the function to take an
arbitrary number of components.

1 files changed, 7 insertions, 6 deletions

diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index ec8a2525ed9..a624c2eb937 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -2343,9 +2343,10 @@ entirely of directory separators.
 @end example
 @end defun
 
-@defun directory-append directory filename
-Combine @var{filename} with @var{directory} by optionally putting a
-slash in the middle.
+@defun directory-append directory &rest components
+Concatenate @var{components} to @var{directory}, inserting a slash
+before the components if @var{directory} or the preceding component
+didn't end with a slash.
 
 @example
 @group
@@ -2354,9 +2355,9 @@ slash in the middle.
 @end group
 @end example
 
-This is almost the same as using @code{concat}, but @var{dirname} may
-or may not end with a slash character, and this function will not
-double that character.
+This is almost the same as using @code{concat}, but @var{dirname} (and
+the non-final components) may or may not end with slash characters,
+and this function will not double those characters.
 @end defun
 
   To convert a directory name to its abbreviation, use this