From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Thu, 2 Dec 2021 12:21:20 +0000 (+0100)
Subject: Make `C-c C-w' copy the executable bits to the new file
X-Git-Tag: emacs-29.0.90~3625^2~12
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=9ea5a915bd1b9458af1587d63170888346e8baec;p=emacs.git

Make `C-c C-w' copy the executable bits to the new file

* lisp/files.el (write-file): When visiting an executable file,
make the new file executable, too (bug#18915).
---

diff --git a/etc/NEWS b/etc/NEWS
index 55733c6895d..eda12142fed 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -75,6 +75,12 @@ time.
 
 * Changes in Emacs 29.1
 
+---
+** 'write-file' will now copy some file mode bits.
+If the current buffer is visiting a file that is executable, the
+'C-c C-w' command will now make the new file executable, too.
+
++++
 ** New user option 'process-error-pause-time'.
 This determines how long to pause Emacs after a process
 filter/sentinel error has been handled.
diff --git a/lisp/files.el b/lisp/files.el
index 07279c4c871..9ed63a60f81 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -4745,7 +4745,6 @@ using \\<minibuffer-local-map>\\[next-history-element].
 If optional second arg CONFIRM is non-nil, this function
 asks for confirmation before overwriting an existing file.
 Interactively, confirmation is required unless you supply a prefix argument."
-;;  (interactive "FWrite file: ")
   (interactive
    (list (if buffer-file-name
 	     (read-file-name "Write file: "
@@ -4756,33 +4755,44 @@ Interactively, confirmation is required unless you supply a prefix argument."
 			    default-directory)
 			   nil nil))
 	 (not current-prefix-arg)))
-  (or (null filename) (string-equal filename "")
-      (progn
-	;; If arg is a directory name,
-	;; use the default file name, but in that directory.
-	(if (directory-name-p filename)
-	    (setq filename (concat filename
-				   (file-name-nondirectory
-				    (or buffer-file-name (buffer-name))))))
-	(and confirm
-	     (file-exists-p filename)
-	     ;; NS does its own confirm dialog.
-	     (not (and (eq (framep-on-display) 'ns)
-		       (listp last-nonmenu-event)
-		       use-dialog-box))
-	     (or (y-or-n-p (format-message
-                            "File `%s' exists; overwrite? " filename))
-		 (user-error "Canceled")))
-	(set-visited-file-name filename (not confirm))))
-  (set-buffer-modified-p t)
-  ;; Make buffer writable if file is writable.
-  (and buffer-file-name
-       (file-writable-p buffer-file-name)
-       (setq buffer-read-only nil))
-  (save-buffer)
-  ;; It's likely that the VC status at the new location is different from
-  ;; the one at the old location.
-  (vc-refresh-state))
+  (let ((old-modes
+         (and buffer-file-name
+              ;; File may have gone away; ignore errors in that case.
+              (ignore-errors (file-modes buffer-file-name)))))
+    (or (null filename) (string-equal filename "")
+        (progn
+	  ;; If arg is a directory name,
+	  ;; use the default file name, but in that directory.
+	  (if (directory-name-p filename)
+	      (setq filename (concat filename
+				     (file-name-nondirectory
+				      (or buffer-file-name (buffer-name))))))
+	  (and confirm
+	       (file-exists-p filename)
+	       ;; NS does its own confirm dialog.
+	       (not (and (eq (framep-on-display) 'ns)
+		         (listp last-nonmenu-event)
+		         use-dialog-box))
+	       (or (y-or-n-p (format-message
+                              "File `%s' exists; overwrite? " filename))
+		   (user-error "Canceled")))
+	  (set-visited-file-name filename (not confirm))))
+    (set-buffer-modified-p t)
+    ;; Make buffer writable if file is writable.
+    (and buffer-file-name
+         (file-writable-p buffer-file-name)
+         (setq buffer-read-only nil))
+    (save-buffer)
+    ;; If the old file was executable, then make the new file
+    ;; executable, too.
+    (when (and old-modes
+               (not (zerop (logand #o111 old-modes))))
+      (set-file-modes buffer-file-name
+                      (logior (logand #o111 old-modes)
+                              (file-modes buffer-file-name))))
+    ;; It's likely that the VC status at the new location is different from
+    ;; the one at the old location.
+    (vc-refresh-state)))
 
 (defun file-extended-attributes (filename)
   "Return an alist of extended attributes of file FILENAME.