* lisp/files.el: Only message when saving if save-silently is nil

(save-silently): New variable.
(files--message): New function.

(find-file-noselect, save-buffer, basic-save-buffer)
(basic-save-buffer-2, save-some-buffers, not-modified)
(append-to-file): Use them.

lisp/files.el

@@ -573,6 +573,12 @@ using \\[read-only-mode]."
 
 Maximum length of the history list is determined by the value
 of `history-length', which see.")
+
+(defvar save-silently nil
+  "If non-nil, avoid messages when saving files.
+Error-related messages will still be printed, but all other
+messages will not.")
+
 
 (put 'ange-ftp-completion-hook-function 'safe-magic t)
 (defun ange-ftp-completion-hook-function (op &rest args)
@@ -1865,6 +1871,13 @@ If that fails, try to open it with `find-file-literally'
 	     out-of-memory-warning-percentage
 	     (file-size-human-readable (* total-free-memory 1024)))))))))
 
+(defun files--message (format &rest args)
+  "Like `message', except sometimes don't print to minibuffer.
+If the variable `save-silently' is non-nil, the message is not
+displayed on the minibuffer."
+  (apply #'message format args)
+  (when save-silently (message nil)))
+
 (defun find-file-noselect (filename &optional nowarn rawfile wildcards)
   "Read file FILENAME into a buffer and return the buffer.
 If a buffer exists visiting FILENAME, return that one, but
@@ -1910,8 +1923,8 @@ the various files."
 	      (or nowarn
 		  find-file-suppress-same-file-warnings
 		  (string-equal filename (buffer-file-name other))
-		  (message "%s and %s are the same file"
-			   filename (buffer-file-name other)))
+		  (files--message "%s and %s are the same file"
+                                  filename (buffer-file-name other)))
 	      ;; Optionally also find that buffer.
 	      (if (or find-file-existing-other-name find-file-visit-truename)
 		  (setq buf other))))
@@ -4641,7 +4654,10 @@ See the subroutine `basic-save-buffer' for more information."
     ;; then Rmail-mbox never displays it due to buffer swapping.  If
     ;; the test is ever re-introduced, be sure to handle saving of
     ;; Rmail files.
-    (if (and modp (buffer-file-name) (not noninteractive))
+    (if (and modp
+             (buffer-file-name)
+             (not noninteractive)
+             (not save-silently))
 	(message "Saving file %s..." (buffer-file-name)))
     (basic-save-buffer)
     (and modp (memq arg '(4 64)) (setq buffer-backed-up nil))))
@@ -4785,7 +4801,7 @@ Before and after saving the buffer, this function runs
 	  (run-hooks 'after-save-hook))
       (or noninteractive
           (not (called-interactively-p 'any))
-          (message "(No changes need to be saved)")))))
+          (files--message "(No changes need to be saved)")))))
 
 ;; This does the "real job" of writing a buffer into its visited file
 ;; and making a backup file.  This is what is normally done
@@ -4858,9 +4874,10 @@ Before and after saving the buffer, this function runs
                                ;; Pass in nil&nil rather than point-min&max
                                ;; cause we're saving the whole buffer.
                                ;; write-region-annotate-functions may use it.
-			       (write-region nil nil
-					     tempname nil  realname
-					     buffer-file-truename 'excl)
+                               (write-region nil nil
+                                             tempname nil  realname
+                                             buffer-file-truename 'excl)
+                               (when save-silently (message nil))
 			       nil)
 			   (file-already-exists t))
 		    ;; The file was somehow created by someone else between
@@ -4905,8 +4922,9 @@ Before and after saving the buffer, this function runs
                 ;; Pass in nil&nil rather than point-min&max to indicate
                 ;; we're saving the buffer rather than just a region.
                 ;; write-region-annotate-functions may make us of it.
-		(write-region nil nil
-			      buffer-file-name nil t buffer-file-truename)
+                (write-region nil nil
+                              buffer-file-name nil t buffer-file-truename)
+                (when save-silently (message nil))
 		(setq success t))
 	    ;; If we get an error writing the new file, and we made
 	    ;; the backup by renaming, undo the backing-up.
@@ -5027,13 +5045,13 @@ change the additional actions you can take on files."
 	  (cond
 	   ((null autosaved-buffers)
             (when (called-interactively-p 'any)
-              (message "(No files need saving)")))
+              (files--message "(No files need saving)")))
 	   ((= (length autosaved-buffers) 1)
-	    (message "(Saved %s)" (car autosaved-buffers)))
+	    (files--message "(Saved %s)" (car autosaved-buffers)))
 	   (t
-	    (message "(Saved %d files: %s)"
-		     (length autosaved-buffers)
-		     (mapconcat 'identity autosaved-buffers ", "))))))))
+	    (files--message "(Saved %d files: %s)"
+                            (length autosaved-buffers)
+                            (mapconcat 'identity autosaved-buffers ", "))))))))
 
 (defun clear-visited-file-modtime ()
   "Clear out records of last mod time of visited file.
@@ -5048,8 +5066,8 @@ It is not a good idea to use this function in Lisp programs, because it
 prints a message in the minibuffer.  Instead, use `set-buffer-modified-p'."
   (declare (interactive-only set-buffer-modified-p))
   (interactive "P")
-  (message (if arg "Modification-flag set"
-	       "Modification-flag cleared"))
+  (files--message (if arg "Modification-flag set"
+                    "Modification-flag cleared"))
   (set-buffer-modified-p arg))
 
 (defun toggle-read-only (&optional arg interactive)
@@ -5083,7 +5101,8 @@ instead of any buffer contents; END is ignored.
 This does character code conversion and applies annotations
 like `write-region' does."
   (interactive "r\nFAppend to file: ")
-  (write-region start end filename t))
+  (prog1 (write-region start end filename t)
+    (when save-silently (message nil))))
 
 (defun file-newest-backup (filename)
   "Return most recent backup file for FILENAME or nil if no backups exist."