(find-file-noselect): Offer to change buffer-read-only

only when the file's read-only status has changed from before
as well as disagreeing with the buffer's current status.
(buffer-file-read-only): New var, local in all buffers.

diff --git a/lisp/files.el b/lisp/files.el
index 167514efcf061afd08b04da747b630b005ae6f0d..75937f7a86dcdb891c6a10643dce1949f9039d2a 100644 (file)
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -197,6 +197,10 @@ If the buffer is visiting a new file, the value is nil.")
 (defvar buffer-file-numbers-unique (not (memq system-type '(windows-nt)))
   "Non-nil means that buffer-file-number uniquely identifies files.")
 
+(defvar buffer-file-read-only nil
+  "Non-nil if visited file was read-only when visited.")
+(make-variable-buffer-local 'buffer-file-read-only)
+
 (defvar file-name-invalid-regexp
   (cond ((and (eq system-type 'ms-dos) (not (msdos-long-file-names)))
         (concat "^\\([^A-Z[-`a-z]\\|..+\\)?:\\|" ; colon except after drive
@@ -1071,16 +1075,19 @@ that are visiting the various files."
              (with-current-buffer buf
 
                ;; Check if a formerly read-only file has become
-               ;; writable and vice versa.
+               ;; writable and vice versa, but if the buffer agrees
+               ;; with the new state of the file, that is ok too.
                (let ((read-only (not (file-writable-p buffer-file-name))))
-                 (unless (eq read-only buffer-read-only)
+                 (unless (or (eq read-only buffer-file-read-only)
+                             (eq read-only buffer-read-only))
                    (when (or nowarn
                              (let ((question 
                                     (format "File %s is %s on disk.  Change buffer mode? "
                                             buffer-file-name
                                             (if read-only "read-only" "writable"))))
                                (y-or-n-p question)))
-                     (setq buffer-read-only read-only))))
+                     (setq buffer-read-only read-only)))
+                 (setq buffer-file-read-only read-only))
 
                (when (not (eq (not (null rawfile))
                               (not (null find-file-literally))))