Don't warn on toggle-read-only calls.

Clarify the documentation of toggle-read-only, and audit the code tree
for uses of toggle-read-only; where appropriate, switch to setting the
variable buffer-read-only or calling toggle-read-only with a (new)
second arg.

* lisp/files.el (toggle-read-only): Doc fix and code cleanup.  New arg
to allow printing the message when called from Lisp.

* lisp/emacs-lisp/bytecomp.el (byte-compile-interactive-only-functions):
Remove toggle-read-only.

* lisp/bindings.el (mode-line-toggle-read-only):
* lisp/dired.el (dired-toggle-read-only):
* lisp/ibuffer.el (ibuffer-do-toggle-read-only): Call toggle-read-only
with non-nil second arg.

* lisp/bs.el (bs-toggle-readonly):
* lisp/buff-menu.el (Buffer-menu-toggle-read-only): Remove
with-no-warnings around toggle-read-only.

* lisp/ffap.el (ffap--toggle-read-only): Accept a list of buffers.
Remove with-no-warnings around toggle-read-only.
(ffap-read-only, ffap-read-only-other-window)
(ffap-read-only-other-frame): Callers changed.

* lisp/help-mode.el: Don't require view package.
(help-mode-finish): Set buffer-read-only instead of calling
toggle-read-only.

* lisp/emacs-lisp/eieio-custom.el (eieio-customize-object):
* lisp/vc/ediff.el (ediff-set-read-only-in-buf-A): Set buffer-read-only
directly.

* lisp/gnus/smime.el (smime-certificate-info): Set buffer-read-only directly,
instead of calling toggle-read-only with a (bogus) argument.

* doc/emacs/buffers.texi (Misc Buffer): Document view-read-only.

* doc/lispref/buffers.texi (Read Only Buffers): Document toggle-read-only
changes.  Reword to account for the fact that read-only is currently not
supported in overlay properties.

1 files changed, 43 insertions, 33 deletions

diff --git a/lisp/files.el b/lisp/files.el
index 53b701dbcbe..7fc7ccc8553 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -4824,41 +4824,51 @@ prints a message in the minibuffer.  Instead, use `set-buffer-modified-p'."
 	       "Modification-flag cleared"))
   (set-buffer-modified-p arg))
 
-(defun toggle-read-only (&optional arg)
-  "Change whether this buffer is read-only.
+(defun toggle-read-only (&optional arg message)
+  "Toggle the read-only state of the current buffer.
 With prefix argument ARG, make the buffer read-only if ARG is
-positive, otherwise make it writable.  If buffer is read-only
-and `view-read-only' is non-nil, enter view mode.
-
-This function is usually the wrong thing to use in a Lisp program.
-It can have side-effects beyond changing the read-only status of a buffer
-\(e.g., enabling view mode), and does not affect read-only regions that
-are caused by text properties.  To make a buffer read-only in Lisp code,
-set `buffer-read-only'.  To ignore read-only status (whether due to text
-properties or buffer state) and make changes, temporarily bind
-`inhibit-read-only'."
+positive; otherwise make it writable.
+
+When making the buffer read-only, enable View mode if
+`view-read-only' is non-nil.  When making the buffer writable,
+disable View mode if View mode is enabled.
+
+If called interactively, or if called from Lisp with MESSAGE
+non-nil, print a message reporting the buffer's new read-only
+status.
+
+Do not call this from a Lisp program unless you really intend to
+do the same thing as the \\[toggle-read-only] command, including
+possibly enabling or disabling View mode.  Also, note that this
+command works by setting the variable `buffer-read-only', which
+does not affect read-only regions caused by text properties.  To
+ignore read-only status in a Lisp program (whether due to text
+properties or buffer state), bind `inhibit-read-only' temporarily
+to a non-nil value."
   (interactive "P")
-  (if (and arg
-           (if (> (prefix-numeric-value arg) 0) buffer-read-only
-             (not buffer-read-only)))  ; If buffer-read-only is set correctly,
-      nil			       ; do nothing.
-    ;; Toggle.
-    (progn
-      (cond
-       ((and buffer-read-only view-mode)
-	(View-exit-and-edit)
-	(make-local-variable 'view-read-only)
-	(setq view-read-only t))		; Must leave view mode.
-       ((and (not buffer-read-only) view-read-only
-	     ;; If view-mode is already active, `view-mode-enter' is a nop.
-	     (not view-mode)
-	     (not (eq (get major-mode 'mode-class) 'special)))
-	(view-mode-enter))
-       (t (setq buffer-read-only (not buffer-read-only))
-	  (force-mode-line-update))))
-    (if (called-interactively-p 'interactive)
-	(message "Read-only %s for this buffer"
-		 (if buffer-read-only "enabled" "disabled")))))
+  (cond
+   ;; Do nothing if `buffer-read-only' already matches the state
+   ;; specified by ARG.
+   ((and arg
+	 (if (> (prefix-numeric-value arg) 0)
+	     buffer-read-only
+	   (not buffer-read-only))))
+   ;; If View mode is enabled, exit it.
+   ((and buffer-read-only view-mode)
+    (View-exit-and-edit)
+    (set (make-local-variable 'view-read-only) t))
+   ;; If `view-read-only' is non-nil, enable View mode.
+   ((and view-read-only
+	 (not buffer-read-only)
+	 (not view-mode)
+	 (not (eq (get major-mode 'mode-class) 'special)))
+    (view-mode-enter))
+   ;; The usual action: flip `buffer-read-only'.
+   (t (setq buffer-read-only (not buffer-read-only))
+      (force-mode-line-update)))
+  (if (or message (called-interactively-p 'interactive))
+      (message "Read-only %s for this buffer"
+	       (if buffer-read-only "enabled" "disabled"))))
 
 (defun insert-file (filename)
   "Insert contents of file FILENAME into buffer after point.