Add file-local-name

* doc/lispref/files.texi (Magic File Names): Add `file-local-name'.
(Unique File Names): Use it.

* etc/NEWS: Mention `file-local-name'.

* lisp/files.el (file-local-name): New defun.
(file-expand-wildcards):
* lisp/eshell/em-tramp.el (eshell/su, eshell/sudo):
* lisp/eshell/esh-ext.el (eshell-remote-command):
* lisp/eshell/esh-proc.el (eshell-gather-process-output):
* lisp/org/ob-core.el (org-babel-local-file-name):
* lisp/progmodes/gud.el (gud-common-init, gud-format-command):
* lisp/progmodes/python.el (python-shell-send-file):
* lisp/shell.el (shell):
* lisp/vc/ediff-diff.el (ediff-same-file-contents):
* lisp/vc/vc-git.el (vc-git-checkin): Use it.

3 files changed, 4 insertions, 6 deletions

diff --git a/lisp/eshell/em-tramp.el b/lisp/eshell/em-tramp.el
index 9105c482b38..3eff20d1a1b 100644
--- a/lisp/eshell/em-tramp.el
+++ b/lisp/eshell/em-tramp.el
@@ -72,8 +72,7 @@ Become another USER during a login session.")
             (let ((user "root")
                   (host (or (file-remote-p default-directory 'host)
                             "localhost"))
-                  (dir (or (file-remote-p default-directory 'localname)
-                           (expand-file-name default-directory)))
+                  (dir (file-local-name (expand-file-name default-directory)))
                   (prefix (file-remote-p default-directory)))
               (dolist (arg args)
                 (if (string-equal arg "-") (setq login t) (setq user arg)))
@@ -111,8 +110,7 @@ Execute a COMMAND as the superuser or another USER.")
             (let ((user (or user "root"))
                   (host (or (file-remote-p default-directory 'host)
                             "localhost"))
-                  (dir (or (file-remote-p default-directory 'localname)
-                           (expand-file-name default-directory)))
+                  (dir (file-local-name (expand-file-name default-directory)))
                   (prefix (file-remote-p default-directory)))
               ;; `eshell-eval-using-options' reads options of COMMAND.
               (while (and (stringp (car orig-args))
diff --git a/lisp/eshell/esh-ext.el b/lisp/eshell/esh-ext.el
index ca62d0cf8b0..4d658cd718e 100644
--- a/lisp/eshell/esh-ext.el
+++ b/lisp/eshell/esh-ext.el
@@ -203,7 +203,7 @@ all the output from the remote command, and sends it all at once,
 causing the user to wonder if anything's really going on..."
   (let ((outbuf (generate-new-buffer " *eshell remote output*"))
         (errbuf (generate-new-buffer " *eshell remote error*"))
-        (command (or (file-remote-p command 'localname) command))
+        (command (file-local-name command))
         (exitcode 1))
     (unwind-protect
         (progn
diff --git a/lisp/eshell/esh-proc.el b/lisp/eshell/esh-proc.el
index 8c6bad089c5..21680df765d 100644
--- a/lisp/eshell/esh-proc.el
+++ b/lisp/eshell/esh-proc.el
@@ -279,7 +279,7 @@ See `eshell-needs-pipe'."
             (let ((process-connection-type
                    (unless (eshell-needs-pipe-p command)
                      process-connection-type))
-                  (command (or (file-remote-p command 'localname) command)))
+                  (command (file-local-name command)))
               (apply 'start-file-process
                      (file-name-nondirectory command) nil
                      ;; `start-process' can't deal with relative filenames.