Add a major-mode for the *Messages* buffer

Ref: http://lists.gnu.org/archive/html/emacs-devel/2010-02/msg00135.html

* lisp/simple.el (messages-buffer-mode): New major mode.
(messages-buffer): New function.

* lisp/startup.el (normal-top-level): Switch mode of *Messages* buffer.

* src/xdisp.c (message_dolog): If we create *Messages*,
switch it to messages-buffer-mode.

* lisp/emacs-lisp/ert.el (ert--force-message-log-buffer-truncation)
(ert-run-test): Use `message-buffer' function.
(ert--force-message-log-buffer-truncation): Ignore read-only.

* lisp/help.el (view-echo-area-messages): Use `message-buffer' function.

* lisp/mail/emacsbug.el (report-emacs-bug): Use `message-buffer' function.

* lisp/gnus/gnus-util.el (gnus-message-with-timestamp-1):
Use `message-buffer' function if available.  Ignore read-only.

* etc/NEWS: Mention this.

diff --git a/etc/NEWS b/etc/NEWS
index 7558fc530521bfc1cd3823e531375cd5b53420c6..6042ed8bf5fbf6e45f1e42147c07b77b0fe73776 100644 (file)
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -93,6 +93,10 @@ simply disabling Transient Mark mode does the same thing.
 ** `initial-buffer-choice' can now specify a function to set up the
 initial buffer.
 
+** The *Messages* buffer is created in a new major mode `messages-buffer-mode',
+and read-only.  Code that might create the *Messages* buffer should
+call the function `messages-buffer' to do so and set the mode.
+
 ** `remember-notes' creates a buffer whose content is saved on kill-emacs.
 You may think of it as a *scratch* buffer whose content is preserved.
 In fact, it was designed as a replacement for *scratch* buffer and can

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 15afc3ad19eb51cfd6b9cef41cc7ff92a6e585d0..ceae81b91e099b346b9f2580d6de562add910f8b 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,14 @@
+2013-09-17  Glenn Morris  <rgm@gnu.org>
+
+       * simple.el (messages-buffer-mode): New major mode.
+       (messages-buffer): New function.
+       * startup.el (normal-top-level): Switch mode of *Messages* buffer.
+       * emacs-lisp/ert.el (ert--force-message-log-buffer-truncation)
+       (ert-run-test): Use `message-buffer' function.
+       (ert--force-message-log-buffer-truncation): Ignore read-only.
+       * help.el (view-echo-area-messages): Use `message-buffer' function.
+       * mail/emacsbug.el (report-emacs-bug): Use `message-buffer' function.
+
 2013-09-17  Stefan Monnier  <monnier@iro.umontreal.ca>
 
        * subr.el (eval-after-load): Preserve evaluation order (bug#15389).

diff --git a/lisp/emacs-lisp/ert.el b/lisp/emacs-lisp/ert.el
index 98576687f3d56ed05131a1930cc39168a222047b..409e4faf4d5e67717d8b4a0ae2407c030380217c 100644 (file)
--- a/lisp/emacs-lisp/ert.el
+++ b/lisp/emacs-lisp/ert.el
@@ -785,7 +785,7 @@ This mainly sets up debugger-related bindings."
   "Immediately truncate *Messages* buffer according to `message-log-max'.
 
 This can be useful after reducing the value of `message-log-max'."
-  (with-current-buffer (get-buffer-create "*Messages*")
+  (with-current-buffer (messages-buffer)
     ;; This is a reimplementation of this part of message_dolog() in xdisp.c:
     ;; if (NATNUMP (Vmessage_log_max))
     ;;   {
@@ -798,7 +798,8 @@ This can be useful after reducing the value of `message-log-max'."
             (end (save-excursion
                    (goto-char (point-max))
                    (forward-line (- message-log-max))
-                   (point))))
+                   (point)))
+            (inhibit-read-only t))
         (delete-region begin end)))))
 
 (defvar ert--running-tests nil
@@ -818,7 +819,7 @@ Returns the result and stores it in ERT-TEST's `most-recent-result' slot."
   (setf (ert-test-most-recent-result ert-test) nil)
   (cl-block error
     (let ((begin-marker
-           (with-current-buffer (get-buffer-create "*Messages*")
+           (with-current-buffer (messages-buffer)
              (point-max-marker))))
       (unwind-protect
           (let ((info (make-ert--test-execution-info
@@ -837,7 +838,7 @@ Returns the result and stores it in ERT-TEST's `most-recent-result' slot."
                   (ert--run-test-internal info))
               (let ((result (ert--test-execution-info-result info)))
                 (setf (ert-test-result-messages result)
-                      (with-current-buffer (get-buffer-create "*Messages*")
+                      (with-current-buffer (messages-buffer)
                         (buffer-substring begin-marker (point-max))))
                 (ert--force-message-log-buffer-truncation)
                 (setq should-form-accu (nreverse should-form-accu))

diff --git a/lisp/gnus/ChangeLog b/lisp/gnus/ChangeLog
index fc8ff9fd695907fe4f57e8ccea7f12d4d220ffa8..2889ead69ed0c31a70ccccb53a46609fda199f9d 100644 (file)
--- a/lisp/gnus/ChangeLog
+++ b/lisp/gnus/ChangeLog
@@ -1,3 +1,8 @@
+2013-09-17  Glenn Morris  <rgm@gnu.org>
+
+       * gnus-util.el (gnus-message-with-timestamp-1):
+       Use `message-buffer' function if available.  Ignore read-only.
+
 2013-09-16  Katsumi Yamaoka  <yamaoka@jpl.org>
 
        * message.el (message-expand-group, message-completion-in-region):

diff --git a/lisp/gnus/gnus-util.el b/lisp/gnus/gnus-util.el
index 1d2ab2da24833dfeac055179d0929eb375abd06c..4f63f4bdbc0a8cf71591d85e01f87fe5d574c5ed 100644 (file)
--- a/lisp/gnus/gnus-util.el
+++ b/lisp/gnus/gnus-util.el
@@ -514,11 +514,14 @@ but also to the ones displayed in the echo area."
                             (> message-log-max 0)
                             (/= (length str) 0))
                    (setq time (current-time))
-                   (with-current-buffer (get-buffer-create "*Messages*")
+                   (with-current-buffer (if (fboundp 'messages-buffer)
+                                            (messages-buffer)
+                                          (get-buffer-create "*Messages*"))
                      (goto-char (point-max))
-                     (insert ,timestamp str "\n")
-                     (forward-line (- message-log-max))
-                     (delete-region (point-min) (point))
+                     (let ((inhibit-read-only t))
+                       (insert ,timestamp str "\n")
+                       (forward-line (- message-log-max))
+                       (delete-region (point-min) (point)))
                      (goto-char (point-max))))
                  str)
                 (gnus-add-timestamp-to-message

diff --git a/lisp/help.el b/lisp/help.el
index 4ec0b99a5939072bcd1d6c006582ed6191544c68..c21d5b8c1d1045be16a77bfcdd687c449e43ffde 100644 (file)
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -1,7 +1,6 @@
 ;;; help.el --- help commands for Emacs
 
-;; Copyright (C) 1985-1986, 1993-1994, 1998-2013 Free Software
-;; Foundation, Inc.
+;; Copyright (C) 1985-1986, 1993-1994, 1998-2013 Free Software Foundation, Inc.
 
 ;; Maintainer: FSF
 ;; Keywords: help, internal
@@ -412,7 +411,7 @@ With argument, display info only for the selected version."
 The number of messages retained in that buffer
 is specified by the variable `message-log-max'."
   (interactive)
-  (with-current-buffer (get-buffer-create "*Messages*")
+  (with-current-buffer (messages-buffer)
     (goto-char (point-max))
     (display-buffer (current-buffer))))
 

diff --git a/lisp/mail/emacsbug.el b/lisp/mail/emacsbug.el
index c1bc7e2e1abc27cf72292282126a46d8d2ce9b66..e045519e8503385c59fb9d72bb83816e709eb56e 100644 (file)
--- a/lisp/mail/emacsbug.el
+++ b/lisp/mail/emacsbug.el
@@ -1,7 +1,7 @@
 ;;; emacsbug.el --- command to report Emacs bugs to appropriate mailing list
 
-;; Copyright (C) 1985, 1994, 1997-1998, 2000-2013 Free Software
-;; Foundation, Inc.
+;; Copyright (C) 1985, 1994, 1997-1998, 2000-2013
+;;   Free Software Foundation, Inc.
 
 ;; Author: K. Shane Hartman
 ;; Maintainer: FSF
@@ -160,7 +160,7 @@ Prompts for bug subject.  Leaves you in a mail buffer."
                             (report-emacs-bug-can-use-osx-open)))
         user-point message-end-point)
     (setq message-end-point
-         (with-current-buffer (get-buffer-create "*Messages*")
+         (with-current-buffer (messages-buffer)
            (point-max-marker)))
     (compose-mail report-emacs-bug-address topic)
     ;; The rest of this does not execute if the user was asked to

diff --git a/lisp/simple.el b/lisp/simple.el
index 593f36d1ee1fe204e4f46534be3e46401e1fc633..54630681a68eaab8100d418494d6ef9c8f3b1e4d 100644 (file)
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -7344,6 +7344,18 @@ and setting it to nil."
         buffer-invisibility-spec)
     (setq buffer-invisibility-spec nil)))
 \f
+(define-derived-mode messages-buffer-mode special-mode "Messages"
+  "Major mode used in the \"*Messages*\" buffer.")
+
+(defun messages-buffer ()
+  "Return the \"*Messages*\" buffer.
+If it does not exist, create and it switch it to `messages-buffer-mode'."
+  (or (get-buffer "*Messages*")
+      (with-current-buffer (get-buffer-create "*Messages*")
+        (messages-buffer-mode)
+        (current-buffer))))
+
+\f
 ;; Minibuffer prompt stuff.
 
 ;;(defun minibuffer-prompt-modification (start end)

diff --git a/lisp/startup.el b/lisp/startup.el
index ec7d73306a28c29173e488e8ba17d11a54f8ca9c..059d771032099c4122fd267d9ff0f800a8c42d5b 100644 (file)
--- a/lisp/startup.el
+++ b/lisp/startup.el
@@ -1,7 +1,6 @@
 ;;; startup.el --- process Emacs shell arguments  -*- lexical-binding: t -*-
 
-;; Copyright (C) 1985-1986, 1992, 1994-2013 Free Software Foundation,
-;; Inc.
+;; Copyright (C) 1985-1986, 1992, 1994-2013 Free Software Foundation, Inc.
 
 ;; Maintainer: FSF
 ;; Keywords: internal
@@ -494,6 +493,7 @@ It is the default value of the variable `top-level'."
     (setq command-line-processed t)
     (let ((dir default-directory))
       (with-current-buffer "*Messages*"
+        (messages-buffer-mode)
         ;; Make it easy to do like "tail -f".
         (set (make-local-variable 'window-point-insertion-type) t)
         ;; Give *Messages* the same default-directory as *scratch*,

diff --git a/src/ChangeLog b/src/ChangeLog
index b4ec77780e4835bfb26e766c2f8898eaf3760677..00b59e89e6746f5f7572f284bc850bfaf0733d8a 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2013-09-17  Glenn Morris  <rgm@gnu.org>
+
+       * xdisp.c (message_dolog): If we create *Messages*,
+       switch it to messages-buffer-mode.
+
 2013-09-17  Paul Eggert  <eggert@cs.ucla.edu>
 
        Don't overuse 'const' in types of locals.

diff --git a/src/xdisp.c b/src/xdisp.c
index 4582002fa0e19f6e67999a2761689388222b7c62..b07aad51bc9886f41cbcb5ff03e05d8c0bdf37b4 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1,7 +1,6 @@
 /* Display generation from window structure and buffer text.
 
-Copyright (C) 1985-1988, 1993-1995, 1997-2013 Free Software Foundation,
-Inc.
+Copyright (C) 1985-1988, 1993-1995, 1997-2013 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -9538,7 +9537,20 @@ message_dolog (const char *m, ptrdiff_t nbytes, bool nlflag, bool multibyte)
 
       old_deactivate_mark = Vdeactivate_mark;
       oldbuf = current_buffer;
-      Fset_buffer (Fget_buffer_create (Vmessages_buffer_name));
+
+      /* Ensure the Messages buffer exists, and switch to it.
+         If we created it, set the major-mode.  */
+      {
+        int newbuffer = 0;
+        if (NILP (Fget_buffer (Vmessages_buffer_name))) newbuffer = 1;
+
+        Fset_buffer (Fget_buffer_create (Vmessages_buffer_name));
+
+        if (newbuffer &&
+            !NILP (Ffboundp (intern ("messages-buffer-mode"))))
+          call0 (intern ("messages-buffer-mode"));
+      }
+
       bset_undo_list (current_buffer, Qt);
 
       oldpoint = message_dolog_marker1;