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.

2 files changed, 5 insertions, 10 deletions

diff --git a/lisp/vc/ediff-diff.el b/lisp/vc/ediff-diff.el
index b1ac32d7019..56bfebb579c 100644
--- a/lisp/vc/ediff-diff.el
+++ b/lisp/vc/ediff-diff.el
@@ -1347,10 +1347,8 @@ arguments to `skip-chars-forward'."
                  ;; located on the same remote host.
                  (apply 'process-file ediff-cmp-program nil nil nil
                         (append ediff-cmp-options
-                                (list (or (file-remote-p f1 'localname)
-                                          (expand-file-name f1))
-                                      (or (file-remote-p f2 'localname)
-                                          (expand-file-name f2)))))
+                                (list (expand-file-name (file-local-name f1))
+                                      (expand-file-name (file-local-name f2)))))
                  ))
             (and (numberp res) (eq res 0)))
 
diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
index 9df581dda5b..ec0e081743d 100644
--- a/lisp/vc/vc-git.el
+++ b/lisp/vc/vc-git.el
@@ -704,13 +704,10 @@ It is based on `log-edit-mode', and has Git-specific extensions.")
           ;; file, to work around the limitation that command-line
           ;; arguments must be in the system codepage, and therefore
           ;; might not support the non-ASCII characters in the log
-          ;; message.
+          ;; message.  Handle also remote files.
           (if (eq system-type 'windows-nt)
-              (if (file-remote-p file1)
-                  (let ((default-directory (file-name-directory file1)))
-                    (file-remote-p
-                     (make-nearby-temp-file "git-msg") 'localname))
-                (make-temp-file "git-msg")))))
+              (let ((default-directory (file-name-directory file1)))
+                (file-local-name (make-nearby-temp-file "git-msg"))))))
     (cl-flet ((boolean-arg-fn
                (argument)
                (lambda (value) (when (equal value "yes") (list argument)))))