(vc-hooks, ewoc): Require.

[gnu-emacs] / lisp / view.el

diff --git a/lisp/view.el b/lisp/view.el
index 2f541fbf360063bc490fc1ce2a9a505d069d51f2..1d2078a4bb8752908c62cf19b96b8606516d5f1a 100644 (file)
--- a/lisp/view.el
+++ b/lisp/view.el
@@ -1,7 +1,7 @@
 ;;; view.el --- peruse file or buffer without editing
 
 ;; Copyright (C) 1985, 1989, 1994, 1995, 1997, 2000, 2001, 2002,
 ;;; view.el --- peruse file or buffer without editing
 
 ;; Copyright (C) 1985, 1989, 1994, 1995, 1997, 2000, 2001, 2002,

-;;   2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+;;   2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

 
 ;; Author: K. Shane Hartman
 ;; Maintainer: Inge Frick <inge@nada.kth.se>
 
 ;; Author: K. Shane Hartman
 ;; Maintainer: Inge Frick <inge@nada.kth.se>


@@ -9,10 +9,10 @@
 
 ;; This file is part of GNU Emacs.
 
 
 ;; This file is part of GNU Emacs.
 

-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs is free software: you can redistribute it and/or modify

 ;; it under the terms of the GNU General Public License as published by
 ;; it under the terms of the GNU General Public License as published by

-;; the Free Software Foundation; either version 3, or (at your option)
-;; any later version.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.

 
 ;; GNU Emacs is distributed in the hope that it will be useful,
 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
 
 ;; GNU Emacs is distributed in the hope that it will be useful,
 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of


@@ -20,9 +20,7 @@
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License

-;; along with GNU Emacs; see the file COPYING.  If not, write to the
-;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-;; Boston, MA 02110-1301, USA.
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

 
 ;;; Commentary:
 
 
 ;;; Commentary:
 


@@ -77,11 +75,15 @@ for all scroll commands in view mode."
   :type 'boolean
   :group 'view)
 
   :type 'boolean
   :group 'view)
 

-(defcustom view-remove-frame-by-deleting nil
+;;;###autoload
+(defcustom view-remove-frame-by-deleting t

   "*Determine how View mode removes a frame no longer needed.
 If nil, make an icon of the frame.  If non-nil, delete the frame."
   :type 'boolean
   "*Determine how View mode removes a frame no longer needed.
 If nil, make an icon of the frame.  If non-nil, delete the frame."
   :type 'boolean

-  :group 'view)
+  :group 'view
+  ;; Changed the default of this to t for Emacs 23.  Users consider
+  ;; frame iconification annoying.
+  :version "23.1")

 
 (defcustom view-exits-all-viewing-windows nil
   "*Non-nil means restore all windows used to view buffer.
 
 (defcustom view-exits-all-viewing-windows nil
   "*Non-nil means restore all windows used to view buffer.


@@ -146,10 +148,11 @@ See RETURN-TO-ALIST argument of function `view-mode-exit' for the format of
 (put 'view-return-to-alist 'permanent-local t)
 
 (defvar view-exit-action nil
 (put 'view-return-to-alist 'permanent-local t)
 
 (defvar view-exit-action nil

-  "nil or a function with one argument (a buffer) called when finished viewing.
-This is local in each buffer being viewed.
-The \\[view-file] and \\[view-file-other-window] commands may set this to
-`kill-buffer'.")
+  "If non-nil, a function with one argument (a buffer) called when finished viewing.
+Commands like \\[view-file] and \\[view-file-other-window] may
+set this to bury or kill the viewed buffer.
+Observe that the buffer viewed might not appear in any window at
+the time this function is called.")

 (make-variable-buffer-local 'view-exit-action)
 
 (defvar view-no-disable-on-exit nil
 (make-variable-buffer-local 'view-exit-action)
 
 (defvar view-no-disable-on-exit nil


@@ -238,14 +241,25 @@ This is local in each buffer, once it is used.")
 \f
 ;;; Commands that enter or exit view mode.
 
 \f
 ;;; Commands that enter or exit view mode.
 

+;; This is used when view mode is exited, to make sure we don't try to
+;; kill a buffer modified by the user.  A buffer in view mode can
+;; become modified if the user types C-x C-q, edits the buffer, then
+;; types C-x C-q again to return to view mode.
+;;;###autoload
+(defun kill-buffer-if-not-modified (buf)
+  "Like `kill-buffer', but does nothing if the buffer is modified."
+  (let ((buf (get-buffer buf)))
+    (and buf (not (buffer-modified-p buf))
+        (kill-buffer buf))))
+

 ;;;###autoload
 (defun view-file (file)
   "View FILE in View mode, returning to previous buffer when done.
 ;;;###autoload
 (defun view-file (file)
   "View FILE in View mode, returning to previous buffer when done.

-Emacs commands editing the buffer contents are not available; instead,
-a special set of commands (mostly letters and punctuation)
-are defined for moving around in the buffer.
+Emacs commands editing the buffer contents are not available; instead, a
+special set of commands (mostly letters and punctuation) are defined for
+moving around in the buffer.

 Space scrolls forward, Delete scrolls backward.
 Space scrolls forward, Delete scrolls backward.

-For list of all View commands, type H or h while viewing.
+For a list of all View commands, type H or h while viewing.

 
 This command runs the normal hook `view-mode-hook'."
   (interactive "fView file: ")
 
 This command runs the normal hook `view-mode-hook'."
   (interactive "fView file: ")


@@ -258,58 +272,71 @@ This command runs the normal hook `view-mode-hook'."
        (progn
          (switch-to-buffer buffer)
          (message "Not using View mode because the major mode is special"))
        (progn
          (switch-to-buffer buffer)
          (message "Not using View mode because the major mode is special"))

-      (view-buffer buffer (and (not had-a-buf) 'kill-buffer)))))
+      (view-buffer buffer (and (not had-a-buf) 'kill-buffer-if-not-modified)))))

 
 ;;;###autoload
 (defun view-file-other-window (file)
   "View FILE in View mode in another window.
 
 ;;;###autoload
 (defun view-file-other-window (file)
   "View FILE in View mode in another window.

-Return that window to its previous buffer when done.
+When done, return that window to its previous buffer, and kill the
+buffer visiting FILE if unmodified and if it wasn't visited before.
+

 Emacs commands editing the buffer contents are not available; instead,
 a special set of commands (mostly letters and punctuation)
 are defined for moving around in the buffer.
 Space scrolls forward, Delete scrolls backward.
 Emacs commands editing the buffer contents are not available; instead,
 a special set of commands (mostly letters and punctuation)
 are defined for moving around in the buffer.
 Space scrolls forward, Delete scrolls backward.

-For list of all View commands, type H or h while viewing.
+For a list of all View commands, type H or h while viewing.

 
 This command runs the normal hook `view-mode-hook'."
   (interactive "fIn other window view file: ")
   (unless (file-exists-p file) (error "%s does not exist" file))
 
 This command runs the normal hook `view-mode-hook'."
   (interactive "fIn other window view file: ")
   (unless (file-exists-p file) (error "%s does not exist" file))

-  (let ((had-a-buf (get-file-buffer file)))
-    (view-buffer-other-window (find-file-noselect file) nil
-                             (and (not had-a-buf) 'kill-buffer))))
+  (let ((had-a-buf (get-file-buffer file))
+       (buf-to-view (find-file-noselect file)))
+    (view-buffer-other-window buf-to-view nil
+                             (and (not had-a-buf)
+                                  'kill-buffer-if-not-modified))))

 
 ;;;###autoload
 (defun view-file-other-frame (file)
   "View FILE in View mode in another frame.
 
 ;;;###autoload
 (defun view-file-other-frame (file)
   "View FILE in View mode in another frame.

-Maybe delete other frame and/or return to previous buffer when done.
+When done, kill the buffer visiting FILE if unmodified and if it wasn't
+visited before; also, maybe delete other frame and/or return to previous
+buffer.
+

 Emacs commands editing the buffer contents are not available; instead,
 a special set of commands (mostly letters and punctuation)
 are defined for moving around in the buffer.
 Space scrolls forward, Delete scrolls backward.
 Emacs commands editing the buffer contents are not available; instead,
 a special set of commands (mostly letters and punctuation)
 are defined for moving around in the buffer.
 Space scrolls forward, Delete scrolls backward.

-For list of all View commands, type H or h while viewing.
+For a list of all View commands, type H or h while viewing.

 
 This command runs the normal hook `view-mode-hook'."
   (interactive "fIn other frame view file: ")
   (unless (file-exists-p file) (error "%s does not exist" file))
 
 This command runs the normal hook `view-mode-hook'."
   (interactive "fIn other frame view file: ")
   (unless (file-exists-p file) (error "%s does not exist" file))

-  (let ((had-a-buf (get-file-buffer file)))
-    (view-buffer-other-frame (find-file-noselect file) nil
-                            (and (not had-a-buf) 'kill-buffer))))
+  (let ((had-a-buf (get-file-buffer file))
+       (buf-to-view (find-file-noselect file)))
+    (view-buffer-other-frame buf-to-view nil
+                            (and (not had-a-buf)
+                                 'kill-buffer-if-not-modified))))

 
 
 ;;;###autoload
 (defun view-buffer (buffer &optional exit-action)
   "View BUFFER in View mode, returning to previous buffer when done.
 
 
 ;;;###autoload
 (defun view-buffer (buffer &optional exit-action)
   "View BUFFER in View mode, returning to previous buffer when done.

-Emacs commands editing the buffer contents are not available; instead,
-a special set of commands (mostly letters and punctuation)
-are defined for moving around in the buffer.
+Emacs commands editing the buffer contents are not available; instead, a
+special set of commands (mostly letters and punctuation) are defined for
+moving around in the buffer.

 Space scrolls forward, Delete scrolls backward.
 Space scrolls forward, Delete scrolls backward.

-For list of all View commands, type H or h while viewing.
+For a list of all View commands, type H or h while viewing.

 
 This command runs the normal hook `view-mode-hook'.
 
 Optional argument EXIT-ACTION is either nil or a function with buffer as
 
 This command runs the normal hook `view-mode-hook'.
 
 Optional argument EXIT-ACTION is either nil or a function with buffer as

-argument.  This function is called when finished viewing buffer.
-Use this argument instead of explicitly setting `view-exit-action'."
+argument.  This function is called when finished viewing buffer.  Use
+this argument instead of explicitly setting `view-exit-action'.

 
 

+Do not set EXIT-ACTION to `kill-buffer' when BUFFER visits a
+file: Users may suspend viewing in order to modify the buffer.
+Exiting View mode will then discard the user's edits.  Setting
+EXIT-ACTION to `kill-buffer-if-not-modified' avoids this."

   (interactive "bView buffer: ")
   (let ((undo-window (list (window-buffer) (window-start) (window-point))))
     (switch-to-buffer buffer)
   (interactive "bView buffer: ")
   (let ((undo-window (list (window-buffer) (window-start) (window-point))))
     (switch-to-buffer buffer)


@@ -319,18 +346,18 @@ Use this argument instead of explicitly setting `view-exit-action'."
 ;;;###autoload
 (defun view-buffer-other-window (buffer &optional not-return exit-action)
   "View BUFFER in View mode in another window.
 ;;;###autoload
 (defun view-buffer-other-window (buffer &optional not-return exit-action)
   "View BUFFER in View mode in another window.

-Return to previous buffer when done, unless optional NOT-RETURN is non-nil.
-Emacs commands editing the buffer contents are not available; instead,
-a special set of commands (mostly letters and punctuation)
-are defined for moving around in the buffer.
+Return to previous buffer when done, unless optional NOT-RETURN is
+non-nil.  Emacs commands editing the buffer contents are not available;
+instead, a special set of commands (mostly letters and punctuation) are
+defined for moving around in the buffer.

 Space scrolls forward, Delete scrolls backward.
 Space scrolls forward, Delete scrolls backward.

-For list of all View commands, type H or h while viewing.
+For a list of all View commands, type H or h while viewing.

 
 This command runs the normal hook `view-mode-hook'.
 
 Optional argument EXIT-ACTION is either nil or a function with buffer as
 
 This command runs the normal hook `view-mode-hook'.
 
 Optional argument EXIT-ACTION is either nil or a function with buffer as

-argument.  This function is called when finished viewing buffer.
-Use this argument instead of explicitly setting `view-exit-action'."
+argument.  This function is called when finished viewing buffer.  Use
+this argument instead of explicitly setting `view-exit-action'."

   (interactive "bIn other window view buffer:\nP")
   (let* ((win                          ; This window will be selected by
          (get-lru-window))             ; switch-to-buffer-other-window below.
   (interactive "bIn other window view buffer:\nP")
   (let* ((win                          ; This window will be selected by
          (get-lru-window))             ; switch-to-buffer-other-window below.


@@ -350,18 +377,18 @@ Use this argument instead of explicitly setting `view-exit-action'."
 ;;;###autoload
 (defun view-buffer-other-frame (buffer &optional not-return exit-action)
   "View BUFFER in View mode in another frame.
 ;;;###autoload
 (defun view-buffer-other-frame (buffer &optional not-return exit-action)
   "View BUFFER in View mode in another frame.

-Return to previous buffer when done, unless optional NOT-RETURN is non-nil.
-Emacs commands editing the buffer contents are not available; instead,
-a special set of commands (mostly letters and punctuation)
-are defined for moving around in the buffer.
+Return to previous buffer when done, unless optional NOT-RETURN is
+non-nil.  Emacs commands editing the buffer contents are not available;
+instead, a special set of commands (mostly letters and punctuation) are
+defined for moving around in the buffer.

 Space scrolls forward, Delete scrolls backward.
 Space scrolls forward, Delete scrolls backward.

-For list of all View commands, type H or h while viewing.
+For a list of all View commands, type H or h while viewing.

 
 This command runs the normal hook `view-mode-hook'.
 
 Optional argument EXIT-ACTION is either nil or a function with buffer as
 
 This command runs the normal hook `view-mode-hook'.
 
 Optional argument EXIT-ACTION is either nil or a function with buffer as

-argument.  This function is called when finished viewing buffer.
-Use this argument instead of explicitly setting `view-exit-action'."
+argument.  This function is called when finished viewing buffer.  Use
+this argument instead of explicitly setting `view-exit-action'."

   (interactive "bView buffer in other frame: \nP")
   (let ((return-to
         (and (not not-return) (cons (selected-window) t)))) ; Old window.
   (interactive "bView buffer in other frame: \nP")
   (let ((return-to
         (and (not not-return) (cons (selected-window) t)))) ; Old window.


@@ -375,7 +402,8 @@ Use this argument instead of explicitly setting `view-exit-action'."
   ;; bindings instead of using the \\[] construction.  The reason for this
   ;; is that most commands have more than one key binding.
   "Toggle View mode, a minor mode for viewing text but not editing it.
   ;; bindings instead of using the \\[] construction.  The reason for this
   ;; is that most commands have more than one key binding.
   "Toggle View mode, a minor mode for viewing text but not editing it.

-With ARG, turn View mode on iff ARG is positive.
+With prefix argument ARG, turn View mode on if ARG is positive, otherwise
+turn it off.

 
 Emacs commands that do not change the buffer contents are available as usual.
 Kill commands insert text in kill buffers but do not delete.  Other commands
 
 Emacs commands that do not change the buffer contents are available as usual.
 Kill commands insert text in kill buffers but do not delete.  Other commands


@@ -494,34 +522,73 @@ Entry to view-mode runs the normal hook `view-mode-hook'."
       (setq buffer-read-only view-old-buffer-read-only)))
 
 ;;;###autoload
       (setq buffer-read-only view-old-buffer-read-only)))
 
 ;;;###autoload

-(defun view-mode-enter (&optional return-to exit-action) "\
-Enter View mode and set up exit from view mode depending on optional arguments.
-If RETURN-TO is non-nil it is added as an element to the buffer local alist
-`view-return-to-alist'.
-Save EXIT-ACTION in buffer local variable `view-exit-action'.
-It should be either nil or a function that takes a buffer as argument.
-This function will be called by `view-mode-exit'.
-
-RETURN-TO is either nil, meaning do nothing when exiting view mode, or
-it has the format (WINDOW OLD-WINDOW . OLD-BUF-INFO).
-WINDOW is a window used for viewing.
-OLD-WINDOW is nil or the window to select after viewing.
-OLD-BUF-INFO tells what to do with WINDOW when exiting.  It is one of:
-1) nil       Do nothing.
-2) t         Delete WINDOW or, if it is the only window, its frame.
+(defun view-return-to-alist-update (buffer &optional item)
+  "Update `view-return-to-alist' of buffer BUFFER.
+Remove from `view-return-to-alist' all entries referencing dead
+windows.  Optional argument ITEM non-nil means add ITEM to
+`view-return-to-alist' after purging.  For a decsription of items
+that can be added see the RETURN-TO-ALIST argument of the
+function `view-mode-exit'.  If `view-return-to-alist' contains an
+entry for the selected window, purge that entry from
+`view-return-to-alist' before adding ITEM."
+  (with-current-buffer buffer
+    (when view-return-to-alist
+      (let* ((list view-return-to-alist)
+            entry entry-window last)
+       (while list
+         (setq entry (car list))
+         (setq entry-window (car entry))
+         (if (and (windowp entry-window)
+                  (or (and item (eq entry-window (selected-window)))
+                      (not (window-live-p entry-window))))
+             ;; Remove that entry.
+             (if last
+                 (setcdr last (cdr list))
+               (setq view-return-to-alist
+                     (cdr view-return-to-alist)))
+           ;; Leave entry alone.
+           (setq last entry))
+         (setq list (cdr list)))))
+    ;; Add ITEM.
+    (when item
+      (setq view-return-to-alist
+           (cons item view-return-to-alist)))))
+
+;;;###autoload
+(defun view-mode-enter (&optional return-to exit-action)
+  "Enter View mode and set up exit from view mode depending on optional arguments.
+RETURN-TO non-nil means add RETURN-TO as an element to the buffer
+local alist `view-return-to-alist'.  Save EXIT-ACTION in buffer
+local variable `view-exit-action'.  It should be either nil or a
+function that takes a buffer as argument.  This function will be
+called by `view-mode-exit'.
+
+RETURN-TO is either nil, meaning do nothing when exiting view
+mode, or must have the format (WINDOW OLD-WINDOW . OLD-BUF-INFO).
+WINDOW is the window used for viewing.  OLD-WINDOW is nil or the
+window to select after viewing.  OLD-BUF-INFO tells what to do
+with WINDOW when exiting.  It is one of:
+1) nil            Do nothing.
+2) t              Delete WINDOW or, if it is the only window and
+                  `view-remove-frame-by-deleting' is non-nil, its
+                  frame.

 3) (OLD-BUFF START POINT)  Display buffer OLD-BUFF with displayed text
 3) (OLD-BUFF START POINT)  Display buffer OLD-BUFF with displayed text

-                           starting at START and point at POINT in WINDOW.
-4) quit-window   Do `quit-window' in WINDOW.
+                  starting at START and point at POINT in WINDOW.
+4) quit-window    Do `quit-window' in WINDOW.
+5) keep-frame     Like case 2) but do not delete the frame.

 
 

-For list of all View commands, type H or h while viewing.
+For a list of all View commands, type H or h while viewing.

 
 This function runs the normal hook `view-mode-hook'."
 
 This function runs the normal hook `view-mode-hook'."

-  (if return-to
-      (let ((entry (assq (car return-to) view-return-to-alist)))
-       (if entry (setcdr entry (cdr return-to))
-         (setq view-return-to-alist (cons return-to view-return-to-alist)))))
-  (if exit-action (setq view-exit-action exit-action))
-  (unless view-mode                    ; Do nothing if already in view mode.
+  (when return-to
+    (let ((entry (assq (car return-to) view-return-to-alist)))
+      (if entry
+         (setcdr entry (cdr return-to))
+       (setq view-return-to-alist (cons return-to view-return-to-alist)))))
+  (when exit-action
+    (setq view-exit-action exit-action))
+
+  (unless view-mode

     (view-mode-enable)
     (force-mode-line-update)
     (unless view-inhibit-help-message
     (view-mode-enable)
     (force-mode-line-update)
     (unless view-inhibit-help-message


@@ -531,88 +598,106 @@ View mode: type \\[help-command] for help, \\[describe-mode] for commands, \\[Vi
 \f
 (defun view-mode-exit (&optional return-to-alist exit-action all-win)
   "Exit View mode in various ways, depending on optional arguments.
 \f
 (defun view-mode-exit (&optional return-to-alist exit-action all-win)
   "Exit View mode in various ways, depending on optional arguments.

-RETURN-TO-ALIST, EXIT-ACTION and ALL-WIN determine what to do after exit.
-EXIT-ACTION is nil or a function that is called with current buffer as
-argument.
-RETURN-TO-ALIST is an alist that for some of the windows displaying the
-current buffer, associate information on what to do with those windows.
-If ALL-WIN or the variable `view-exits-all-viewing-windows' is non-nil,
-then all windows on RETURN-TO-ALIST are restored to their old state.
-Otherwise only the selected window is affected (if it is on RETURN-TO-ALIST).
-
-Elements of RETURN-TO-ALIST have the format (WINDOW OLD-WINDOW . OLD-BUF-INFO).
-WINDOW is a window displaying the current buffer.
-OLD-WINDOW is nil or a window to select after viewing.
-OLD-BUF-INFO is information on what to do with WINDOW and is one of:
-1) nil       Do nothing.
-2) t         Delete WINDOW and, if it is the only window, its frame.
+RETURN-TO-ALIST, EXIT-ACTION and ALL-WIN determine what to do
+after exit.  EXIT-ACTION is nil or a function that is called with
+current buffer as argument.
+
+RETURN-TO-ALIST is an alist that, for some of the windows
+displaying the current buffer, maintains information on what to
+do when exiting those windows.  If ALL-WIN is non-nil or the
+variable `view-exits-all-viewing-windows' is non-nil,
+view-mode-exit attempts to restore all windows showing the
+current buffer to their old state.  Otherwise, only the selected
+window is affected (provided it is on RETURN-TO-ALIST).
+
+Elements of RETURN-TO-ALIST must have the format
+  (WINDOW OLD-WINDOW . OLD-BUF-INFO) where
+
+WINDOW is a window displaying the current buffer and OLD-WINDOW
+is either nil or a window to select after viewing.  OLD-BUF-INFO
+provides information on what to do with WINDOW and may be one of:
+1) nil            Do nothing.
+2) t              Delete WINDOW and, if it is the only window and
+                  `view-remove-frame-by-deleting' is non-nil, its
+                  frame.

 3) (OLD-BUF START POINT)  Display buffer OLD-BUF with displayed text
 3) (OLD-BUF START POINT)  Display buffer OLD-BUF with displayed text

-                          starting at START and point at POINT in WINDOW.
-4) quit-window   Do `quit-window' in WINDOW.
-
-If one of the WINDOW in RETURN-TO-ALIST is the selected window and the
-corresponding OLD-WINDOW is a live window, then select OLD-WINDOW."
-  (setq all-win
-       (and return-to-alist (or all-win view-exits-all-viewing-windows)))
-  (if view-mode                ; Only do something if in view mode.
-      (let* ((buffer (current-buffer))
-            window notlost
-            (sel-old (assq (selected-window) return-to-alist))
-            (alist (cond
-                    (all-win           ; Try to restore all windows.
-                     (append return-to-alist nil)) ; Copy.
-                    (sel-old           ; Only selected window.
-                     (list sel-old))))
-            (old-window (if sel-old (car (cdr sel-old)))))
-       (if all-win                     ; Follow chains of old-windows.
-           (let ((c (length alist)) a)
-             (while (and (> c 0)       ; Safety if mutually refering windows.
-                         (or (not (window-live-p old-window))
-                             (eq buffer (window-buffer old-window)))
-                         (setq a (assq old-window alist)))
-               (setq c (1- c))
-               (setq old-window (car (cdr a))))
-             (if (or (zerop c) (not (window-live-p old-window)))
-                 (setq old-window (selected-window)))))
-       (or view-no-disable-on-exit
-           (view-mode-disable))
-       (while alist                    ; Restore windows with info.
-         (setq notlost nil)
-         (if (and (window-live-p (setq window (car (car alist))))
+                  starting at START and point at POINT in WINDOW.
+4) quit-window    Do `quit-window' in WINDOW.
+5) keep-frame     Like case 2) but do not delete the frame.
+
+If one of the WINDOW in RETURN-TO-ALIST is the selected window
+and the corresponding OLD-WINDOW is a live window, then select
+OLD-WINDOW."
+  (when view-mode                  ; Only do something if in view mode.
+    (setq all-win
+         (and return-to-alist
+              (or all-win view-exits-all-viewing-windows)))
+    (let* ((buffer (current-buffer))
+          window notlost
+          (sel-old (assq (selected-window) return-to-alist))
+          (alist (cond
+                  (all-win                ; Try to restore all windows.
+                   (append return-to-alist nil)) ; Copy.
+                  (sel-old                     ; Only selected window.
+                   (list sel-old))))
+          (old-window (if sel-old (car (cdr sel-old)))))
+      (if all-win                       ; Follow chains of old-windows.
+         (let ((c (length alist)) a)
+           (while (and (> c 0)   ; Safety if mutually refering windows.
+                       (or (not (window-live-p old-window))
+                           (eq buffer (window-buffer old-window)))
+                       (setq a (assq old-window alist)))
+             (setq c (1- c))
+             (setq old-window (car (cdr a))))
+           (if (or (zerop c) (not (window-live-p old-window)))
+               (setq old-window (selected-window)))))
+      (unless view-no-disable-on-exit
+       (view-mode-disable))
+      (while alist                         ; Restore windows with info.
+       (setq notlost nil)
+       (when (and (window-live-p (setq window (car (car alist))))

                   (eq buffer (window-buffer window)))
                   (eq buffer (window-buffer window)))

-             (let ((frame (window-frame window))
-                   (old-buf-info (cdr (cdr (car alist)))))
-               (if all-win (select-window window))
-               (cond
-                ((and (consp old-buf-info) ; Case 3.
-                      (buffer-live-p (car old-buf-info)))
-                 (set-window-buffer window (car old-buf-info)) ; old-buf
-                 (set-window-start window (car (cdr old-buf-info)))
-                 (set-window-point window (car (cdr (cdr old-buf-info)))))
-                ((eq old-buf-info 'quit-window)
-                 (quit-window))        ; Case 4.
-                ((not (eq old-buf-info t)) nil) ; Not case 2, do nothing.
-                ((not (one-window-p t)) (delete-window))
-                ((not (eq frame (next-frame)))
-                 ;; Not the only frame, so can safely be removed.
-                 (if view-remove-frame-by-deleting
-                     (delete-frame frame)
-                   (setq notlost t)    ; Keep the window. See below.
-                   (iconify-frame frame))))))
-         ;; If a frame is removed by iconifying it, then the window is not
-         ;; really lost.  In this case we keep the entry in
-         ;; view-return-to-alist so that if the user deiconifies the frame
-         ;; and then press q, then the frame is iconified again.
-         (unless notlost
+         (let ((frame (window-frame window))
+               (old-buf-info (cdr (cdr (car alist)))))
+           (if all-win (select-window window))
+           (cond
+            ((and (consp old-buf-info)         ; Case 3.
+                  (buffer-live-p (car old-buf-info)))
+             (set-window-buffer window (car old-buf-info)) ; old-buf
+             (set-window-start window (car (cdr old-buf-info)))
+             (set-window-point window (car (cdr (cdr old-buf-info)))))
+            ((eq old-buf-info 'quit-window)
+             (quit-window))                    ; Case 4.
+            (old-buf-info                      ; Case 2 or 5.
+             (cond
+              ((not (one-window-p t))          ; Not only window.
+               (delete-window))
+              ((eq old-buf-info 'keep-frame)   ; Case 5.
+               (bury-buffer))
+              ((not (eq frame (next-frame)))  ; Case 2 and only window.
+               ;; Not the only frame, so can safely be removed.
+               (if view-remove-frame-by-deleting
+                   (delete-frame frame)
+                 (setq notlost t)         ; Keep the window. See below.
+                 (iconify-frame frame))))))))
+       ;; If a frame is removed by iconifying it, the window is not
+       ;; really lost.  In this case we keep the entry in
+       ;; `view-return-to-alist' so that if the user deiconifies the
+       ;; frame and then hits q, the frame is iconified again.
+       (unless notlost
+         (with-current-buffer buffer

            (setq view-return-to-alist
            (setq view-return-to-alist

-                 (delete (car alist) view-return-to-alist)))
-         (setq alist (cdr alist)))
-       (if (window-live-p old-window)  ; still existing window
-           (select-window old-window))
-       (when exit-action
-         (setq view-exit-action nil)
-         (funcall exit-action buffer))
-       (force-mode-line-update))))
+                 (delete (car alist) view-return-to-alist))))
+       (setq alist (cdr alist)))
+      (when (window-live-p old-window)
+       ;; old-window is still alive => select it.
+       (select-window old-window))
+      (when exit-action
+       ;; Don't do that: If the user wants to quit the *Help* buffer a
+       ;; second time it won't have any effect.
+;;;    (setq view-exit-action nil)
+       (funcall exit-action buffer))
+      (force-mode-line-update))))

 \f
 (defun View-exit ()
   "Exit View mode but stay in current buffer."
 \f
 (defun View-exit ()
   "Exit View mode but stay in current buffer."


@@ -989,29 +1074,29 @@ for highlighting the match that is found."
               times (if no "no " "") regexp)
       (sit-for 4))))
 
               times (if no "no " "") regexp)
       (sit-for 4))))
 

+;; This is the dumb approach, looking at each line.  The original
+;; version of this function looked like it might have been trying to
+;; do something clever, but not succeeding:
+;; http://lists.gnu.org/archive/html/bug-gnu-emacs/2007-09/msg00073.html

 (defun view-search-no-match-lines (times regexp)
 (defun view-search-no-match-lines (times regexp)

-  ;; Search for the TIMESt occurrence of line with no match for REGEXP.
-  (let ((back (and (< times 0) (setq times (- times)) -1))
-       n)
-    (while (> times 0)
-      (save-excursion (beginning-of-line (if back (- times) (1+ times)))
-                     (setq n (point)))
-      (setq times
-           (cond
-            ((< (count-lines (point) n) times) -1) ; Not enough lines.
-            ((or (null (re-search-forward regexp nil t back))
-                 (if back (and (< (match-end 0) n)
-                               (> (count-lines (match-end 0) n) 1))
-                   (and (< n (match-beginning 0))
-                        (> (count-lines n (match-beginning 0)) 1))))
-             0)                        ; No match within lines.
-            (back (count-lines (max n (match-beginning 0)) (match-end 0)))
-            (t (count-lines (match-beginning 0) (min n (match-end 0))))))
-      (goto-char n))
-    (and (zerop times) (looking-at "^.*$"))))
-
+  "Search for the TIMESth occurrence of a line with no match for REGEXP.
+If such a line is found, return non-nil and set the match-data to that line.
+If TIMES is negative, search backwards."
+  (let ((step (if (>= times 0) 1
+                (setq times (- times))
+                -1)))
+    ;; Note that we do not check the current line.
+    (while (and (> times 0)
+                (zerop (forward-line step)))
+      ;; (forward-line 1) returns 0 on moving within the last line.
+      (if (eobp)
+          (setq times -1)
+        (or (re-search-forward regexp (line-end-position) t)
+            (setq times (1- times))))))
+  (and (zerop times)
+       (looking-at ".*")))

 
 (provide 'view)
 
 
 (provide 'view)
 

-;;; arch-tag: 6d0ace36-1d12-4de3-8de3-1fa3231636d7
+;; arch-tag: 6d0ace36-1d12-4de3-8de3-1fa3231636d7

 ;;; view.el ends here
 ;;; view.el ends here