ChangeLog fix.

[gnu-emacs] / lisp / window.el

diff --git a/lisp/window.el b/lisp/window.el
index ba9a74a1746f37d5d2f784aa52d03f5b8fe006bf..e8e1c6149fd77e285b8dfb96dcf45ca58dc5057f 100644 (file)
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -1,17 +1,18 @@
 ;;; window.el --- GNU Emacs window commands aside from those written in C
 
 ;; Copyright (C) 1985, 1989, 1992, 1993, 1994, 2000, 2001, 2002,
 ;;; window.el --- GNU Emacs window commands aside from those written in C
 
 ;; Copyright (C) 1985, 1989, 1992, 1993, 1994, 2000, 2001, 2002,

-;;   2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+;;   2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+;;   Free Software Foundation, Inc.

 
 ;; Maintainer: FSF
 ;; Keywords: internal
 
 ;; This file is part of GNU Emacs.
 
 
 ;; Maintainer: FSF
 ;; Keywords: internal
 
 ;; 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


@@ -19,9 +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:
 


@@ -29,6 +28,8 @@
 
 ;;; Code:
 
 
 ;;; Code:
 

+(eval-when-compile (require 'cl))
+

 (defvar window-size-fixed nil
  "*Non-nil in a buffer means windows displaying the buffer are fixed-size.
 If the value is `height', then only the window's height is fixed.
 (defvar window-size-fixed nil
  "*Non-nil in a buffer means windows displaying the buffer are fixed-size.
 If the value is `height', then only the window's height is fixed.


@@ -39,19 +40,20 @@ unless you explicitly change the size, or Emacs has no other choice.")
 (make-variable-buffer-local 'window-size-fixed)
 
 (defmacro save-selected-window (&rest body)
 (make-variable-buffer-local 'window-size-fixed)
 
 (defmacro save-selected-window (&rest body)

-  "Execute BODY, then select the window that was selected before BODY.
+  "Execute BODY, then select the previously selected window.

 The value returned is the value of the last form in BODY.
 
 The value returned is the value of the last form in BODY.
 

+This macro saves and restores the selected window, as well as the
+selected window in each frame.  If the previously selected window
+is no longer live, then whatever window is selected at the end of
+BODY remains selected.  If the previously selected window of some
+frame is no longer live at the end of BODY, that frame's selected
+window is left alone.
+

 This macro saves and restores the current buffer, since otherwise
 This macro saves and restores the current buffer, since otherwise

-its normal operation could potentially make a different
-buffer current.  It does not alter the buffer list ordering.
-
-This macro saves and restores the selected window, as well as
-the selected window in each frame.  If the previously selected
-window of some frame is no longer live at the end of BODY, that
-frame's selected window is left alone.  If the selected window is
-no longer live, then whatever window is selected at the end of
-BODY remains selected."
+its normal operation could make a different buffer current.  The
+order of recently selected windows and the buffer list ordering
+are not altered by this macro (unless they are altered in BODY)."

   `(let ((save-selected-window-window (selected-window))
         ;; It is necessary to save all of these, because calling
         ;; select-window changes frame-selected-window for whatever
   `(let ((save-selected-window-window (selected-window))
         ;; It is necessary to save all of these, because calling
         ;; select-window changes frame-selected-window for whatever


@@ -65,13 +67,19 @@ BODY remains selected."
         (dolist (elt save-selected-window-alist)
           (and (frame-live-p (car elt))
                (window-live-p (cdr elt))
         (dolist (elt save-selected-window-alist)
           (and (frame-live-p (car elt))
                (window-live-p (cdr elt))

-               (set-frame-selected-window (car elt) (cdr elt))))
-        (if (window-live-p save-selected-window-window)
-            (select-window save-selected-window-window))))))
+               (set-frame-selected-window (car elt) (cdr elt) 'norecord)))
+        (when (window-live-p save-selected-window-window)
+          (select-window save-selected-window-window 'norecord))))))

 
 (defun window-body-height (&optional window)
 
 (defun window-body-height (&optional window)

-  "Return number of lines in window WINDOW for actual buffer text.
-This does not include the mode line (if any) or the header line (if any)."
+  "Return number of lines in WINDOW available for actual buffer text.
+WINDOW defaults to the selected window.
+
+The return value does not include the mode line or the header
+line, if any.  If a line at the bottom of the window is only
+partially visible, that line is included in the return value.
+If you do not want to include a partially visible bottom line
+in the return value, use `window-text-height' instead."

   (or window (setq window (selected-window)))
   (if (window-minibuffer-p window)
       (window-height window)
   (or window (setq window (selected-window)))
   (if (window-minibuffer-p window)
       (window-height window)


@@ -80,6 +88,16 @@ This does not include the mode line (if any) or the header line (if any)."
                (if mode-line-format 1 0)
                (if header-line-format 1 0))))))
 
                (if mode-line-format 1 0)
                (if header-line-format 1 0))))))
 

+;; See discussion in bug#4543.
+(defun window-full-height-p (&optional window)
+  "Return non-nil if WINDOW is not the result of a vertical split.
+WINDOW defaults to the selected window.  (This function is not
+appropriate for minibuffers.)"
+  (unless window
+    (setq window (selected-window)))
+  (= (window-height window)
+     (window-height (frame-root-window (window-frame window)))))
+

 (defun one-window-p (&optional nomini all-frames)
   "Return non-nil if the selected window is the only window.
 Optional arg NOMINI non-nil means don't count the minibuffer
 (defun one-window-p (&optional nomini all-frames)
   "Return non-nil if the selected window is the only window.
 Optional arg NOMINI non-nil means don't count the minibuffer


@@ -99,11 +117,18 @@ If ALL-FRAMES is anything else, count only the selected frame."
        (next-window base-window (if nomini 'arg) all-frames))))
 
 (defun window-current-scroll-bars (&optional window)
        (next-window base-window (if nomini 'arg) all-frames))))
 
 (defun window-current-scroll-bars (&optional window)

-  "Return the current scroll-bar settings in window WINDOW.
-Value is a cons (VERTICAL . HORIZONTAL) where VERTICAL specifies the
-current location of the vertical scroll-bars (left, right, or nil),
-and HORIZONTAL specifies the current location of the horizontal scroll
-bars (top, bottom, or nil)."
+  "Return the current scroll bar settings for WINDOW.
+WINDOW defaults to the selected window.
+
+The return value is a cons cell (VERTICAL . HORIZONTAL) where
+VERTICAL specifies the current location of the vertical scroll
+bars (`left', `right', or nil), and HORIZONTAL specifies the
+current location of the horizontal scroll bars (`top', `bottom',
+or nil).
+
+Unlike `window-scroll-bars', this function reports the scroll bar
+type actually used, once frame defaults and `scroll-bar-mode' are
+taken into account."

   (let ((vert (nth 2 (window-scroll-bars window)))
        (hor nil))
     (when (or (eq vert t) (eq hor t))
   (let ((vert (nth 2 (window-scroll-bars window)))
        (hor nil))
     (when (or (eq vert t) (eq hor t))


@@ -116,34 +141,53 @@ bars (top, bottom, or nil)."
     (cons vert hor)))
 
 (defun walk-windows (proc &optional minibuf all-frames)
     (cons vert hor)))
 
 (defun walk-windows (proc &optional minibuf all-frames)

-  "Cycle through all visible windows, calling PROC for each one.
-PROC is called with a window as argument.
+  "Cycle through all windows, calling PROC for each one.
+PROC must specify a function with a window as its sole argument.
+The optional arguments MINIBUF and ALL-FRAMES specify the set of
+windows to include in the walk, see also `next-window'.

 
 

-Optional second arg MINIBUF t means count the minibuffer window even
-if not active.  MINIBUF nil or omitted means count the minibuffer only if
-it is active.  MINIBUF neither t nor nil means not to count the
-minibuffer even if it is active.
+MINIBUF t means include the minibuffer window even if the
+minibuffer is not active.  MINIBUF nil or omitted means include
+the minibuffer window only if the minibuffer is active.  Any
+other value means do not include the minibuffer window even if
+the minibuffer is active.

 
 Several frames may share a single minibuffer; if the minibuffer
 
 Several frames may share a single minibuffer; if the minibuffer

-counts, all windows on all frames that share that minibuffer count
-too.  Therefore, if you are using a separate minibuffer frame
-and the minibuffer is active and MINIBUF says it counts,
-`walk-windows' includes the windows in the frame from which you
-entered the minibuffer, as well as the minibuffer window.
-
-ALL-FRAMES is the optional third argument.
-ALL-FRAMES nil or omitted means cycle within the frames as specified above.
-ALL-FRAMES = `visible' means include windows on all visible frames.
-ALL-FRAMES = 0 means include windows on all visible and iconified frames.
-ALL-FRAMES = t means include windows on all frames including invisible frames.
-If ALL-FRAMES is a frame, it means include windows on that frame.
-Anything else means restrict to the selected frame."
-  ;; If we start from the minibuffer window, don't fail to come back to it.
-  (if (window-minibuffer-p (selected-window))
-      (setq minibuf t))
+is active, all windows on all frames that share that minibuffer
+are included too.  Therefore, if you are using a separate
+minibuffer frame and the minibuffer is active and MINIBUF says it
+counts, `walk-windows' includes the windows in the frame from
+which you entered the minibuffer, as well as the minibuffer
+window.
+
+ALL-FRAMES nil or omitted means cycle through all windows on the
+ selected frame, plus the minibuffer window if specified by the
+ MINIBUF argument, see above.  If the minibuffer counts, cycle
+ through all windows on all frames that share that minibuffer
+ too.
+ALL-FRAMES t means cycle through all windows on all existing
+ frames.
+ALL-FRAMES `visible' means cycle through all windows on all
+ visible frames.
+ALL-FRAMES 0 means cycle through all windows on all visible and
+ iconified frames.
+ALL-FRAMES a frame means cycle through all windows on that frame
+ only.
+Anything else means cycle through all windows on the selected
+ frame and no others.
+
+This function changes neither the order of recently selected
+windows nor the buffer list."
+  ;; If we start from the minibuffer window, don't fail to come
+  ;; back to it.
+  (when (window-minibuffer-p (selected-window))
+    (setq minibuf t))
+  ;; Make sure to not mess up the order of recently selected
+  ;; windows.  Use `save-selected-window' and `select-window'
+  ;; with second argument non-nil for this purpose.

   (save-selected-window
   (save-selected-window

-    (if (framep all-frames)
-       (select-window (frame-first-window all-frames)))
+    (when (framep all-frames)
+      (select-window (frame-first-window all-frames) 'norecord))

     (let* (walk-windows-already-seen
           (walk-windows-current (selected-window)))
       (while (progn
     (let* (walk-windows-already-seen
           (walk-windows-current (selected-window)))
       (while (progn


@@ -157,32 +201,15 @@ Anything else means restrict to the selected frame."
 (defun get-window-with-predicate (predicate &optional minibuf
                                            all-frames default)
   "Return a window satisfying PREDICATE.
 (defun get-window-with-predicate (predicate &optional minibuf
                                            all-frames default)
   "Return a window satisfying PREDICATE.

-
-This function cycles through all visible windows using `walk-windows',
-calling PREDICATE on each one.  PREDICATE is called with a window as
-argument.  The first window for which PREDICATE returns a non-nil
-value is returned.  If no window satisfies PREDICATE, DEFAULT is
-returned.
-
-Optional second arg MINIBUF t means count the minibuffer window even
-if not active.  MINIBUF nil or omitted means count the minibuffer only if
-it is active.  MINIBUF neither t nor nil means not to count the
-minibuffer even if it is active.
-
-Several frames may share a single minibuffer; if the minibuffer
-counts, all windows on all frames that share that minibuffer count
-too.  Therefore, if you are using a separate minibuffer frame
-and the minibuffer is active and MINIBUF says it counts,
-`walk-windows' includes the windows in the frame from which you
-entered the minibuffer, as well as the minibuffer window.
-
-ALL-FRAMES is the optional third argument.
-ALL-FRAMES nil or omitted means cycle within the frames as specified above.
-ALL-FRAMES = `visible' means include windows on all visible frames.
-ALL-FRAMES = 0 means include windows on all visible and iconified frames.
-ALL-FRAMES = t means include windows on all frames including invisible frames.
-If ALL-FRAMES is a frame, it means include windows on that frame.
-Anything else means restrict to the selected frame."
+More precisely, cycle through all windows using `walk-windows',
+calling the function PREDICATE on each one of them with the
+window as its sole argument.  Return the first window for which
+PREDICATE returns non-nil.  If no window satisfies PREDICATE,
+return DEFAULT.
+
+The optional arguments MINIBUF and ALL-FRAMES specify the set of
+windows to include.  See `walk-windows' for the meaning of these
+arguments."

   (catch 'found
     (walk-windows #'(lambda (window)
                      (when (funcall predicate window)
   (catch 'found
     (walk-windows #'(lambda (window)
                      (when (funcall predicate window)


@@ -193,40 +220,38 @@ Anything else means restrict to the selected frame."
 (defalias 'some-window 'get-window-with-predicate)
 
 ;; This should probably be written in C (i.e., without using `walk-windows').
 (defalias 'some-window 'get-window-with-predicate)
 
 ;; This should probably be written in C (i.e., without using `walk-windows').

-(defun get-buffer-window-list (buffer &optional minibuf frame)
-  "Return list of all windows displaying BUFFER, or nil if none.
-BUFFER can be a buffer or a buffer name.
-See `walk-windows' for the meaning of MINIBUF and FRAME."
-  (let ((buffer (if (bufferp buffer) buffer (get-buffer buffer))) windows)
+(defun get-buffer-window-list (&optional buffer-or-name minibuf all-frames)
+  "Return list of all windows displaying BUFFER-OR-NAME, or nil if none.
+BUFFER-OR-NAME may be a buffer or the name of an existing buffer
+and defaults to the current buffer.
+
+The optional arguments MINIBUF and ALL-FRAMES specify the set of
+windows to consider.  See `walk-windows' for the precise meaning
+of these arguments."
+  (let ((buffer (cond
+                ((not buffer-or-name) (current-buffer))
+                ((bufferp buffer-or-name) buffer-or-name)
+                (t (get-buffer buffer-or-name))))
+       windows)

     (walk-windows (function (lambda (window)
                              (if (eq (window-buffer window) buffer)
                                  (setq windows (cons window windows)))))
     (walk-windows (function (lambda (window)
                              (if (eq (window-buffer window) buffer)
                                  (setq windows (cons window windows)))))

-                 minibuf frame)
+                 minibuf all-frames)

     windows))
 
 (defun minibuffer-window-active-p (window)
     windows))
 
 (defun minibuffer-window-active-p (window)

-  "Return t if WINDOW (a minibuffer window) is now active."
+  "Return t if WINDOW is the currently active minibuffer window."

   (eq window (active-minibuffer-window)))
 \f
 (defun count-windows (&optional minibuf)
    "Return the number of visible windows.
   (eq window (active-minibuffer-window)))
 \f
 (defun count-windows (&optional minibuf)
    "Return the number of visible windows.

-This counts the windows in the selected frame and (if the minibuffer is
-to be counted) its minibuffer frame (if that's not the same frame).
-The optional arg MINIBUF non-nil means count the minibuffer
-even if it is inactive."
+The optional argument MINIBUF specifies whether the minibuffer
+window shall be counted.  See `walk-windows' for the precise
+meaning of this argument."

    (let ((count 0))
      (walk-windows (lambda (w) (setq count (+ count 1)))
                   minibuf)
      count))
    (let ((count 0))
      (walk-windows (lambda (w) (setq count (+ count 1)))
                   minibuf)
      count))

-
-(defun window-safely-shrinkable-p (&optional window)
-  "Non-nil if the WINDOW can be shrunk without shrinking other windows.
-If WINDOW is nil or omitted, it defaults to the currently selected window."
-  (with-selected-window (or window (selected-window))
-    (let ((edges (window-edges)))
-      (or (= (nth 2 edges) (nth 2 (window-edges (previous-window))))
-         (= (nth 0 edges) (nth 0 (window-edges (next-window))))))))
-

 \f
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; `balance-windows' subroutines using `window-tree'
 \f
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; `balance-windows' subroutines using `window-tree'


@@ -424,26 +449,28 @@ Arguments WINDOW, DELTA and HORIZONTAL are passed on to that function."
       (dolist (c childs)
         (bw-balance-sub c cw ch)))))
 
       (dolist (c childs)
         (bw-balance-sub c cw ch)))))
 

-;;; A different solution to balance-windows
-

 (defun window-fixed-size-p (&optional window direction)
 (defun window-fixed-size-p (&optional window direction)

-  "Non-nil if WINDOW cannot be resized in DIRECTION.
-DIRECTION can be nil (i.e. any), `height' or `width'."
+  "Return t if WINDOW cannot be resized in DIRECTION.
+WINDOW defaults to the selected window.  DIRECTION can be
+nil (i.e. any), `height' or `width'."

   (with-current-buffer (window-buffer window)
   (with-current-buffer (window-buffer window)

-    (let ((fixed (and (boundp 'window-size-fixed) window-size-fixed)))
-      (when fixed
-       (not (and direction
-                 (member (cons direction window-size-fixed)
-                         '((height . width) (width . height)))))))))
+    (when (and (boundp 'window-size-fixed) window-size-fixed)
+      (not (and direction
+               (member (cons direction window-size-fixed)
+                       '((height . width) (width . height))))))))
+
+;;; A different solution to balance-windows.

 
 (defvar window-area-factor 1
   "Factor by which the window area should be over-estimated.
 This is used by `balance-windows-area'.
 Changing this globally has no effect.")
 
 (defvar window-area-factor 1
   "Factor by which the window area should be over-estimated.
 This is used by `balance-windows-area'.
 Changing this globally has no effect.")

+(make-variable-buffer-local 'window-area-factor)

 
 (defun balance-windows-area ()
   "Make all visible windows the same area (approximately).
 
 (defun balance-windows-area ()
   "Make all visible windows the same area (approximately).

-See also `window-area-factor' to change the relative size of specific buffers."
+See also `window-area-factor' to change the relative size of
+specific buffers."

   (interactive)
   (let* ((unchanged 0) (carry 0) (round 0)
          ;; Remove fixed-size windows.
   (interactive)
   (let* ((unchanged 0) (carry 0) (round 0)
          ;; Remove fixed-size windows.


@@ -517,11 +544,700 @@ See also `window-area-factor' to change the relative size of specific buffers."
     ;; (message "Done in %d rounds" round)
     ))
 
     ;; (message "Done in %d rounds" round)
     ))
 

-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

 \f
 \f

+(defcustom display-buffer-function nil
+  "If non-nil, function to call to handle `display-buffer'.
+It will receive two args, the buffer and a flag which if non-nil
+means that the currently selected window is not acceptable.  It
+should choose or create a window, display the specified buffer in
+it, and return the window.
+
+Commands such as `switch-to-buffer-other-window' and
+`find-file-other-window' work using this function."
+  :type '(choice
+         (const nil)
+         (function :tag "function"))
+  :group 'windows)
+
+(defcustom special-display-buffer-names nil
+  "List of names of buffers that should be displayed specially.
+Displaying a buffer with `display-buffer' or `pop-to-buffer', if
+its name is in this list, displays the buffer in a way specified
+by `special-display-function'.  `special-display-popup-frame'
+\(the default for `special-display-function') usually displays
+the buffer in a separate frame made with the parameters specified
+by `special-display-frame-alist'.  If `special-display-function'
+has been set to some other function, that function is called with
+the buffer as first, and nil as second argument.
+
+Alternatively, an element of this list can be specified as
+\(BUFFER-NAME FRAME-PARAMETERS), where BUFFER-NAME is a buffer
+name and FRAME-PARAMETERS an alist of \(PARAMETER . VALUE) pairs.
+`special-display-popup-frame' will interpret such pairs as frame
+parameters when it creates a special frame, overriding the
+corresponding values from `special-display-frame-alist'.
+
+As a special case, if FRAME-PARAMETERS contains (same-window . t)
+`special-display-popup-frame' displays that buffer in the
+selected window.  If FRAME-PARAMETERS contains (same-frame . t),
+it displays that buffer in a window on the selected frame.
+
+If `special-display-function' specifies some other function than
+`special-display-popup-frame', that function is called with the
+buffer named BUFFER-NAME as first, and FRAME-PARAMETERS as second
+argument.
+
+Finally, an element of this list can be also specified as
+\(BUFFER-NAME FUNCTION OTHER-ARGS).  In that case,
+`special-display-popup-frame' will call FUNCTION with the buffer
+named BUFFER-NAME as first argument, and OTHER-ARGS as the
+second.  If `special-display-function' specifies some other
+function, that function is called with the buffer named
+BUFFER-NAME as first, and the element's cdr as second argument.
+
+If this variable appears \"not to work\", because you added a
+name to it but the corresponding buffer is displayed in the
+selected window, look at the values of `same-window-buffer-names'
+and `same-window-regexps'.  Those variables take precedence over
+this one.
+
+See also `special-display-regexps'."
+  :type '(repeat
+         (choice :tag "Buffer"
+                 :value ""
+                 (string :format "%v")
+                 (cons :tag "With parameters"
+                       :format "%v"
+                       :value ("" . nil)
+                       (string :format "%v")
+                       (repeat :tag "Parameters"
+                               (cons :format "%v"
+                                     (symbol :tag "Parameter")
+                                     (sexp :tag "Value"))))
+                 (list :tag "With function"
+                       :format "%v"
+                       :value ("" . nil)
+                       (string :format "%v")
+                       (function :tag "Function")
+                       (repeat :tag "Arguments" (sexp)))))
+  :group 'windows
+  :group 'frames)
+
+;;;###autoload
+(put 'special-display-buffer-names 'risky-local-variable t)
+
+(defcustom special-display-regexps nil
+  "List of regexps saying which buffers should be displayed specially.
+Displaying a buffer with `display-buffer' or `pop-to-buffer', if
+any regexp in this list matches its name, displays it specially
+using `special-display-function'.  `special-display-popup-frame'
+\(the default for `special-display-function') usually displays
+the buffer in a separate frame made with the parameters specified
+by `special-display-frame-alist'.  If `special-display-function'
+has been set to some other function, that function is called with
+the buffer as first, and nil as second argument.
+
+Alternatively, an element of this list can be specified as
+\(REGEXP FRAME-PARAMETERS), where REGEXP is a regexp as above and
+FRAME-PARAMETERS an alist of (PARAMETER . VALUE) pairs.
+`special-display-popup-frame' will then interpret these pairs as
+frame parameters when creating a special frame for a buffer whose
+name matches REGEXP, overriding the corresponding values from
+`special-display-frame-alist'.
+
+As a special case, if FRAME-PARAMETERS contains (same-window . t)
+`special-display-popup-frame' displays buffers matching REGEXP in
+the selected window.  \(same-frame . t) in FRAME-PARAMETERS means
+to display such buffers in a window on the selected frame.
+
+If `special-display-function' specifies some other function than
+`special-display-popup-frame', that function is called with the
+buffer whose name matched REGEXP as first, and FRAME-PARAMETERS
+as second argument.
+
+Finally, an element of this list can be also specified as
+\(REGEXP FUNCTION OTHER-ARGS).  `special-display-popup-frame'
+will then call FUNCTION with the buffer whose name matched
+REGEXP as first, and OTHER-ARGS as second argument.  If
+`special-display-function' specifies some other function, that
+function is called with the buffer whose name matched REGEXP
+as first, and the element's cdr as second argument.
+
+If this variable appears \"not to work\", because you added a
+name to it but the corresponding buffer is displayed in the
+selected window, look at the values of `same-window-buffer-names'
+and `same-window-regexps'.  Those variables take precedence over
+this one.
+
+See also `special-display-buffer-names'."
+  :type '(repeat
+         (choice :tag "Buffer"
+                 :value ""
+                 (regexp :format "%v")
+                 (cons :tag "With parameters"
+                       :format "%v"
+                       :value ("" . nil)
+                       (regexp :format "%v")
+                       (repeat :tag "Parameters"
+                               (cons :format "%v"
+                                     (symbol :tag "Parameter")
+                                     (sexp :tag "Value"))))
+                 (list :tag "With function"
+                       :format "%v"
+                       :value ("" . nil)
+                       (regexp :format "%v")
+                       (function :tag "Function")
+                       (repeat :tag "Arguments" (sexp)))))
+  :group 'windows
+  :group 'frames)
+
+(defun special-display-p (buffer-name)
+  "Return non-nil if a buffer named BUFFER-NAME gets a special frame.
+More precisely, return t if `special-display-buffer-names' or
+`special-display-regexps' contain a string entry equaling or
+matching BUFFER-NAME.  If `special-display-buffer-names' or
+`special-display-regexps' contain a list entry whose car equals
+or matches BUFFER-NAME, the return value is the cdr of that
+entry."
+  (let (tmp)
+    (cond
+     ((not (stringp buffer-name)))
+     ((member buffer-name special-display-buffer-names)
+      t)
+     ((setq tmp (assoc buffer-name special-display-buffer-names))
+      (cdr tmp))
+     ((catch 'found
+       (dolist (regexp special-display-regexps)
+         (cond
+          ((stringp regexp)
+           (when (string-match-p regexp buffer-name)
+             (throw 'found t)))
+          ((and (consp regexp) (stringp (car regexp))
+                (string-match-p (car regexp) buffer-name))
+           (throw 'found (cdr regexp))))))))))
+
+(defcustom special-display-function 'special-display-popup-frame
+  "Function to call for displaying special buffers.
+This function is called with two arguments - the buffer and,
+optionally, a list - and should return a window displaying that
+buffer.  The default value usually makes a separate frame for the
+buffer using `special-display-frame-alist' to specify the frame
+parameters.  See the definition of `special-display-popup-frame'
+for how to specify such a function.
+
+A buffer is special when its name is either listed in
+`special-display-buffer-names' or matches a regexp in
+`special-display-regexps'."
+  :type 'function
+  :group 'frames)
+
+(defcustom same-window-buffer-names nil
+  "List of names of buffers that should appear in the \"same\" window.
+`display-buffer' and `pop-to-buffer' show a buffer whose name is
+on this list in the selected rather than some other window.
+
+An element of this list can be a cons cell instead of just a
+string.  In that case, the cell's car must be a string specifying
+the buffer name.  This is for compatibility with
+`special-display-buffer-names'; the cdr of the cons cell is
+ignored.
+
+See also `same-window-regexps'."
+ :type '(repeat (string :format "%v"))
+ :group 'windows)
+
+(defcustom same-window-regexps nil
+  "List of regexps saying which buffers should appear in the \"same\" window.
+`display-buffer' and `pop-to-buffer' show a buffer whose name
+matches a regexp on this list in the selected rather than some
+other window.
+
+An element of this list can be a cons cell instead of just a
+string.  In that case, the cell's car must be a regexp matching
+the buffer name.  This is for compatibility with
+`special-display-regexps'; the cdr of the cons cell is ignored.
+
+See also `same-window-buffer-names'."
+  :type '(repeat (regexp :format "%v"))
+  :group 'windows)
+
+(defun same-window-p (buffer-name)
+  "Return non-nil if a buffer named BUFFER-NAME would be shown in the \"same\" window.
+This function returns non-nil if `display-buffer' or
+`pop-to-buffer' would show a buffer named BUFFER-NAME in the
+selected rather than \(as usual\) some other window.  See
+`same-window-buffer-names' and `same-window-regexps'."
+  (cond
+   ((not (stringp buffer-name)))
+   ;; The elements of `same-window-buffer-names' can be buffer
+   ;; names or cons cells whose cars are buffer names.
+   ((member buffer-name same-window-buffer-names))
+   ((assoc buffer-name same-window-buffer-names))
+   ((catch 'found
+      (dolist (regexp same-window-regexps)
+       ;; The elements of `same-window-regexps' can be regexps
+       ;; or cons cells whose cars are regexps.
+       (when (or (and (stringp regexp)
+                      (string-match regexp buffer-name))
+                 (and (consp regexp) (stringp (car regexp))
+                      (string-match-p (car regexp) buffer-name)))
+         (throw 'found t)))))))
+
+(defcustom pop-up-frames nil
+  "Whether `display-buffer' should make a separate frame.
+If nil, never make a separate frame.
+If the value is `graphic-only', make a separate frame
+on graphic displays only.
+Any other non-nil value means always make a separate frame."
+  :type '(choice
+         (const :tag "Never" nil)
+         (const :tag "On graphic displays only" graphic-only)
+         (const :tag "Always" t))
+  :group 'windows)
+
+(defcustom display-buffer-reuse-frames nil
+  "Non-nil means `display-buffer' should reuse frames.
+If the buffer in question is already displayed in a frame, raise
+that frame."
+  :type 'boolean
+  :version "21.1"
+  :group 'windows)
+
+(defcustom pop-up-windows t
+  "Non-nil means `display-buffer' should make a new window."
+  :type 'boolean
+  :group 'windows)
+
+(defcustom split-window-preferred-function 'split-window-sensibly
+  "Function called by `display-buffer' routines to split a window.
+This function is called with a window as single argument and is
+supposed to split that window and return the new window.  If the
+window can (or shall) not be split, it is supposed to return nil.
+The default is to call the function `split-window-sensibly' which
+tries to split the window in a way which seems most suitable.
+You can customize the options `split-height-threshold' and/or
+`split-width-threshold' in order to have `split-window-sensibly'
+prefer either vertical or horizontal splitting.
+
+If you set this to any other function, bear in mind that the
+`display-buffer' routines may call this function two times.  The
+argument of the first call is the largest window on its frame.
+If that call fails to return a live window, the function is
+called again with the least recently used window as argument.  If
+that call fails too, `display-buffer' will use an existing window
+to display its buffer.
+
+The window selected at the time `display-buffer' was invoked is
+still selected when this function is called.  Hence you can
+compare the window argument with the value of `selected-window'
+if you intend to split the selected window instead or if you do
+not want to split the selected window."
+  :type 'function
+  :version "23.1"
+  :group 'windows)
+
+(defcustom split-height-threshold 80
+  "Minimum height for splitting windows sensibly.
+If this is an integer, `split-window-sensibly' may split a window
+vertically only if it has at least this many lines.  If this is
+nil, `split-window-sensibly' is not allowed to split a window
+vertically.  If, however, a window is the only window on its
+frame, `split-window-sensibly' may split it vertically
+disregarding the value of this variable."
+  :type '(choice (const nil) (integer :tag "lines"))
+  :version "23.1"
+  :group 'windows)
+
+(defcustom split-width-threshold 160
+  "Minimum width for splitting windows sensibly.
+If this is an integer, `split-window-sensibly' may split a window
+horizontally only if it has at least this many columns.  If this
+is nil, `split-window-sensibly' is not allowed to split a window
+horizontally."
+  :type '(choice (const nil) (integer :tag "columns"))
+  :version "23.1"
+  :group 'windows)
+
+(defun window-splittable-p (window &optional horizontal)
+  "Return non-nil if `split-window-sensibly' may split WINDOW.
+Optional argument HORIZONTAL nil or omitted means check whether
+`split-window-sensibly' may split WINDOW vertically.  HORIZONTAL
+non-nil means check whether WINDOW may be split horizontally.
+
+WINDOW may be split vertically when the following conditions
+hold:
+- `window-size-fixed' is either nil or equals `width' for the
+  buffer of WINDOW.
+- `split-height-threshold' is an integer and WINDOW is at least as
+  high as `split-height-threshold'.
+- When WINDOW is split evenly, the emanating windows are at least
+  `window-min-height' lines tall and can accommodate at least one
+  line plus - if WINDOW has one - a mode line.
+
+WINDOW may be split horizontally when the following conditions
+hold:
+- `window-size-fixed' is either nil or equals `height' for the
+  buffer of WINDOW.
+- `split-width-threshold' is an integer and WINDOW is at least as
+  wide as `split-width-threshold'.
+- When WINDOW is split evenly, the emanating windows are at least
+  `window-min-width' or two (whichever is larger) columns wide."
+  (when (window-live-p window)
+    (with-current-buffer (window-buffer window)
+      (if horizontal
+         ;; A window can be split horizontally when its width is not
+         ;; fixed, it is at least `split-width-threshold' columns wide
+         ;; and at least twice as wide as `window-min-width' and 2 (the
+         ;; latter value is hardcoded).
+         (and (memq window-size-fixed '(nil height))
+              ;; Testing `window-full-width-p' here hardly makes any
+              ;; sense nowadays.  This can be done more intuitively by
+              ;; setting up `split-width-threshold' appropriately.
+              (numberp split-width-threshold)
+              (>= (window-width window)
+                  (max split-width-threshold
+                       (* 2 (max window-min-width 2)))))
+       ;; A window can be split vertically when its height is not
+       ;; fixed, it is at least `split-height-threshold' lines high,
+       ;; and it is at least twice as high as `window-min-height' and 2
+       ;; if it has a modeline or 1.
+       (and (memq window-size-fixed '(nil width))
+            (numberp split-height-threshold)
+            (>= (window-height window)
+                (max split-height-threshold
+                     (* 2 (max window-min-height
+                               (if mode-line-format 2 1))))))))))
+
+(defun split-window-sensibly (window)
+  "Split WINDOW in a way suitable for `display-buffer'.
+If `split-height-threshold' specifies an integer, WINDOW is at
+least `split-height-threshold' lines tall and can be split
+vertically, split WINDOW into two windows one above the other and
+return the lower window.  Otherwise, if `split-width-threshold'
+specifies an integer, WINDOW is at least `split-width-threshold'
+columns wide and can be split horizontally, split WINDOW into two
+windows side by side and return the window on the right.  If this
+can't be done either and WINDOW is the only window on its frame,
+try to split WINDOW vertically disregarding any value specified
+by `split-height-threshold'.  If that succeeds, return the lower
+window.  Return nil otherwise.
+
+By default `display-buffer' routines call this function to split
+the largest or least recently used window.  To change the default
+customize the option `split-window-preferred-function'.
+
+You can enforce this function to not split WINDOW horizontally,
+by setting \(or binding) the variable `split-width-threshold' to
+nil.  If, in addition, you set `split-height-threshold' to zero,
+chances increase that this function does split WINDOW vertically.
+
+In order to not split WINDOW vertically, set \(or bind) the
+variable `split-height-threshold' to nil.  Additionally, you can
+set `split-width-threshold' to zero to make a horizontal split
+more likely to occur.
+
+Have a look at the function `window-splittable-p' if you want to
+know how `split-window-sensibly' determines whether WINDOW can be
+split."
+  (or (and (window-splittable-p window)
+          ;; Split window vertically.
+          (with-selected-window window
+            (split-window-vertically)))
+      (and (window-splittable-p window t)
+          ;; Split window horizontally.
+          (with-selected-window window
+            (split-window-horizontally)))
+      (and (eq window (frame-root-window (window-frame window)))
+          (not (window-minibuffer-p window))
+          ;; If WINDOW is the only window on its frame and is not the
+          ;; minibuffer window, try to split it vertically disregarding
+          ;; the value of `split-height-threshold'.
+          (let ((split-height-threshold 0))
+            (when (window-splittable-p window)
+              (with-selected-window window
+                (split-window-vertically)))))))
+
+(defun window--try-to-split-window (window)
+  "Try to split WINDOW.
+Return value returned by `split-window-preferred-function' if it
+represents a live window, nil otherwise."
+      (and (window-live-p window)
+          (not (frame-parameter (window-frame window) 'unsplittable))
+          (let ((new-window
+                 ;; Since `split-window-preferred-function' might
+                 ;; throw an error use `condition-case'.
+                 (condition-case nil
+                     (funcall split-window-preferred-function window)
+                   (error nil))))
+            (and (window-live-p new-window) new-window))))
+
+(defun window--frame-usable-p (frame)
+  "Return FRAME if it can be used to display a buffer."
+  (when (frame-live-p frame)
+    (let ((window (frame-root-window frame)))
+      ;; `frame-root-window' may be an internal window which is considered
+      ;; "dead" by `window-live-p'.  Hence if `window' is not live we
+      ;; implicitly know that `frame' has a visible window we can use.
+      (unless (and (window-live-p window)
+                   (or (window-minibuffer-p window)
+                       ;; If the window is soft-dedicated, the frame is usable.
+                       ;; Actually, even if the window is really dedicated,
+                       ;; the frame is still usable by splitting it.
+                       ;; At least Emacs-22 allowed it, and it is desirable
+                       ;; when displaying same-frame windows.
+                       nil ; (eq t (window-dedicated-p window))
+                       ))
+       frame))))
+
+(defcustom even-window-heights t
+  "If non-nil `display-buffer' will try to even window heights.
+Otherwise `display-buffer' will leave the window configuration
+alone.  Heights are evened only when `display-buffer' chooses a
+window that appears above or below the selected window."
+  :type 'boolean
+  :group 'windows)
+
+(defun window--even-window-heights (window)
+  "Even heights of WINDOW and selected window.
+Do this only if these windows are vertically adjacent to each
+other, `even-window-heights' is non-nil, and the selected window
+is higher than WINDOW."
+  (when (and even-window-heights
+            (not (eq window (selected-window)))
+            ;; Don't resize minibuffer windows.
+            (not (window-minibuffer-p (selected-window)))
+            (> (window-height (selected-window)) (window-height window))
+            (eq (window-frame window) (window-frame (selected-window)))
+            (let ((sel-edges (window-edges (selected-window)))
+                  (win-edges (window-edges window)))
+              (and (= (nth 0 sel-edges) (nth 0 win-edges))
+                   (= (nth 2 sel-edges) (nth 2 win-edges))
+                   (or (= (nth 1 sel-edges) (nth 3 win-edges))
+                       (= (nth 3 sel-edges) (nth 1 win-edges))))))
+    (let ((window-min-height 1))
+      ;; Don't throw an error if we can't even window heights for
+      ;; whatever reason.
+      (condition-case nil
+         (enlarge-window (/ (- (window-height window) (window-height)) 2))
+       (error nil)))))
+
+(defun window--display-buffer-1 (window)
+  "Raise the frame containing WINDOW.
+Do not raise the selected frame.  Return WINDOW."
+  (let* ((frame (window-frame window))
+        (visible (frame-visible-p frame)))
+    (unless (or (not visible)
+               ;; Assume the selected frame is already visible enough.
+               (eq frame (selected-frame))
+               ;; Assume the frame from which we invoked the minibuffer
+               ;; is visible.
+               (and (minibuffer-window-active-p (selected-window))
+                    (eq frame (window-frame (minibuffer-selected-window)))))
+      (raise-frame frame))
+    window))
+
+(defun window--display-buffer-2 (buffer window &optional dedicated)
+  "Display BUFFER in WINDOW and make its frame visible.
+Set `window-dedicated-p' to DEDICATED if non-nil.
+Return WINDOW."
+  (when (and (buffer-live-p buffer) (window-live-p window))
+    (set-window-buffer window buffer)
+    (when dedicated
+      (set-window-dedicated-p window dedicated))
+    (window--display-buffer-1 window)))
+
+(defvar display-buffer-mark-dedicated nil
+  "If non-nil, `display-buffer' marks the windows it creates as dedicated.
+The actual non-nil value of this variable will be copied to the
+`window-dedicated-p' flag.")
+
+(defun display-buffer (buffer-or-name &optional not-this-window frame)
+  "Make buffer BUFFER-OR-NAME appear in some window but don't select it.
+BUFFER-OR-NAME must be a buffer or the name of an existing
+buffer.  Return the window chosen to display BUFFER-OR-NAME or
+nil if no such window is found.
+
+Optional argument NOT-THIS-WINDOW non-nil means display the
+buffer in a window other than the selected one, even if it is
+already displayed in the selected window.
+
+Optional argument FRAME specifies which frames to investigate
+when the specified buffer is already displayed.  If the buffer is
+already displayed in some window on one of these frames simply
+return that window.  Possible values of FRAME are:
+
+`visible' - consider windows on all visible frames.
+
+0 - consider windows on all visible or iconified frames.
+
+t - consider windows on all frames.
+
+A specific frame - consider windows on that frame only.
+
+nil - consider windows on the selected frame \(actually the
+last non-minibuffer frame\) only.  If, however, either
+`display-buffer-reuse-frames' or `pop-up-frames' is non-nil
+\(non-nil and not graphic-only on a text-only terminal),
+consider all visible or iconified frames."
+  (interactive "BDisplay buffer:\nP")
+  (let* ((can-use-selected-window
+         ;; The selected window is usable unless either NOT-THIS-WINDOW
+         ;; is non-nil, it is dedicated to its buffer, or it is the
+         ;; `minibuffer-window'.
+         (not (or not-this-window
+                  (window-dedicated-p (selected-window))
+                  (window-minibuffer-p))))
+        (buffer (if (bufferp buffer-or-name)
+                    buffer-or-name
+                  (get-buffer buffer-or-name)))
+        (name-of-buffer (buffer-name buffer))
+        ;; On text-only terminals do not pop up a new frame when
+        ;; `pop-up-frames' equals graphic-only.
+        (use-pop-up-frames (if (eq pop-up-frames 'graphic-only)
+                               (display-graphic-p)
+                             pop-up-frames))
+        ;; `frame-to-use' is the frame where to show `buffer' - either
+        ;; the selected frame or the last nonminibuffer frame.
+        (frame-to-use
+         (or (window--frame-usable-p (selected-frame))
+             (window--frame-usable-p (last-nonminibuffer-frame))))
+        ;; `window-to-use' is the window we use for showing `buffer'.
+        window-to-use)
+    (cond
+     ((not (buffer-live-p buffer))
+      (error "No such buffer %s" buffer))
+     (display-buffer-function
+      ;; Let `display-buffer-function' do the job.
+      (funcall display-buffer-function buffer not-this-window))
+     ((and (not not-this-window)
+          (eq (window-buffer (selected-window)) buffer))
+      ;; The selected window already displays BUFFER and
+      ;; `not-this-window' is nil, so use it.
+      (window--display-buffer-1 (selected-window)))
+     ((and can-use-selected-window (same-window-p name-of-buffer))
+      ;; If the buffer's name tells us to use the selected window do so.
+      (window--display-buffer-2 buffer (selected-window)))
+     ((let ((frames (or frame
+                       (and (or use-pop-up-frames
+                                display-buffer-reuse-frames
+                                (not (last-nonminibuffer-frame)))
+                            0)
+                       (last-nonminibuffer-frame))))
+       (setq window-to-use
+             (catch 'found
+               ;; Search frames for a window displaying BUFFER.  Return
+               ;; the selected window only if we are allowed to do so.
+               (dolist (window (get-buffer-window-list buffer 'nomini frames))
+                 (when (or can-use-selected-window
+                           (not (eq (selected-window) window)))
+                   (throw 'found window))))))
+      ;; The buffer is already displayed in some window; use that.
+      (window--display-buffer-1 window-to-use))
+     ((and special-display-function
+          ;; `special-display-p' returns either t or a list of frame
+          ;; parameters to pass to `special-display-function'.
+          (let ((pars (special-display-p name-of-buffer)))
+            (when pars
+              (funcall special-display-function
+                       buffer (if (listp pars) pars))))))
+     ((or use-pop-up-frames (not frame-to-use))
+      ;; We want or need a new frame.
+      (let ((win (frame-selected-window (funcall pop-up-frame-function))))
+        (window--display-buffer-2 buffer win display-buffer-mark-dedicated)))
+     ((and pop-up-windows
+          ;; Make a new window.
+          (or (not (frame-parameter frame-to-use 'unsplittable))
+              ;; If the selected frame cannot be split look at
+              ;; `last-nonminibuffer-frame'.
+              (and (eq frame-to-use (selected-frame))
+                   (setq frame-to-use (last-nonminibuffer-frame))
+                   (window--frame-usable-p frame-to-use)
+                   (not (frame-parameter frame-to-use 'unsplittable))))
+          ;; Attempt to split largest or least recently used window.
+          (setq window-to-use
+                (or (window--try-to-split-window
+                     (get-largest-window frame-to-use t))
+                    (window--try-to-split-window
+                     (get-lru-window frame-to-use t)))))
+      (window--display-buffer-2 buffer window-to-use
+                                display-buffer-mark-dedicated))
+     ((let ((window-to-undedicate
+            ;; When NOT-THIS-WINDOW is non-nil, temporarily dedicate
+            ;; the selected window to its buffer, to avoid that some of
+            ;; the `get-' routines below choose it.  (Bug#1415)
+            (and not-this-window (not (window-dedicated-p))
+                 (set-window-dedicated-p (selected-window) t)
+                 (selected-window))))
+       (unwind-protect
+           (setq window-to-use
+                 ;; Reuse an existing window.
+                 (or (get-lru-window frame-to-use)
+                     (let ((window (get-buffer-window buffer 'visible)))
+                       (unless (and not-this-window
+                                    (eq window (selected-window)))
+                         window))
+                     (get-largest-window 'visible)
+                     (let ((window (get-buffer-window buffer 0)))
+                       (unless (and not-this-window
+                                    (eq window (selected-window)))
+                         window))
+                     (get-largest-window 0)
+                     (frame-selected-window (funcall pop-up-frame-function))))
+         (when (window-live-p window-to-undedicate)
+           ;; Restore dedicated status of selected window.
+           (set-window-dedicated-p window-to-undedicate nil))))
+      (window--even-window-heights window-to-use)
+      (window--display-buffer-2 buffer window-to-use)))))
+
+(defun pop-to-buffer (buffer-or-name &optional other-window norecord)
+  "Select buffer BUFFER-OR-NAME in some window, preferably a different one.
+BUFFER-OR-NAME may be a buffer, a string \(a buffer name), or
+nil.  If BUFFER-OR-NAME is a string not naming an existent
+buffer, create a buffer with that name.  If BUFFER-OR-NAME is
+nil, choose some other buffer.
+
+If `pop-up-windows' is non-nil, windows can be split to display
+the buffer.  If optional second arg OTHER-WINDOW is non-nil,
+insist on finding another window even if the specified buffer is
+already visible in the selected window, and ignore
+`same-window-regexps' and `same-window-buffer-names'.
+
+If the window to show BUFFER-OR-NAME is not on the selected
+frame, raise that window's frame and give it input focus.
+
+This function returns the buffer it switched to.  This uses the
+function `display-buffer' as a subroutine; see the documentation
+of `display-buffer' for additional customization information.
+
+Optional third arg NORECORD non-nil means do not put this buffer
+at the front of the list of recently selected ones."
+  (let ((buffer
+         ;; FIXME: This behavior is carried over from the previous C version
+         ;; of pop-to-buffer, but really we should use just
+         ;; `get-buffer' here.
+         (if (null buffer-or-name) (other-buffer (current-buffer))
+           (or (get-buffer buffer-or-name)
+               (let ((buf (get-buffer-create buffer-or-name)))
+                 (set-buffer-major-mode buf)
+                 buf))))
+       (old-window (selected-window))
+       (old-frame (selected-frame))
+       new-window new-frame)
+    (set-buffer buffer)
+    (setq new-window (display-buffer buffer other-window))
+    (unless (eq new-window old-window)
+      ;; `display-buffer' has chosen another window, select it.
+      (select-window new-window norecord)
+      (setq new-frame (window-frame new-window))
+      (unless (eq new-frame old-frame)
+       ;; `display-buffer' has chosen another frame, make sure it gets
+       ;; input focus and is risen.
+       (select-frame-set-input-focus new-frame)))
+    buffer))
+

 ;; I think this should be the default; I think people will prefer it--rms.
 (defcustom split-window-keep-point t
 ;; I think this should be the default; I think people will prefer it--rms.
 (defcustom split-window-keep-point t

-  "*If non-nil, \\[split-window-vertically] keeps the original point \
+  "If non-nil, \\[split-window-vertically] keeps the original point \

 in both children.
 This is often more convenient for editing.
 If nil, adjust point in each of the two windows to minimize redisplay.
 in both children.
 This is often more convenient for editing.
 If nil, adjust point in each of the two windows to minimize redisplay.


@@ -533,16 +1249,17 @@ point in both children."
   :type 'boolean
   :group 'windows)
 
   :type 'boolean
   :group 'windows)
 

-(defun split-window-vertically (&optional arg)
-  "Split current window into two windows, one above the other.
-The uppermost window gets ARG lines and the other gets the rest.
-Negative ARG means select the size of the lowermost window instead.
-With no argument, split equally or close to it.
-Both windows display the same buffer now current.
+(defun split-window-vertically (&optional size)
+  "Split selected window into two windows, one above the other.
+The upper window gets SIZE lines and the lower one gets the rest.
+SIZE negative means the lower window gets -SIZE lines and the
+upper one the rest.  With no argument, split windows equally or
+close to it.  Both windows display the same buffer, now current.

 
 

-If the variable `split-window-keep-point' is non-nil, both new windows
-will get the same value of point as the current window.  This is often
-more convenient for editing.  The upper window is the selected window.
+If the variable `split-window-keep-point' is non-nil, both new
+windows will get the same value of point as the selected window.
+This is often more convenient for editing.  The upper window is
+the selected window.

 
 Otherwise, we choose window starts so as to minimize the amount of
 redisplay; this is convenient on slow terminals.  The new selected
 
 Otherwise, we choose window starts so as to minimize the amount of
 redisplay; this is convenient on slow terminals.  The new selected


@@ -554,100 +1271,102 @@ Regardless of the value of `split-window-keep-point', the upper
 window is the original one and the return value is the new, lower
 window."
   (interactive "P")
 window is the original one and the return value is the new, lower
 window."
   (interactive "P")

-  (let ((old-w (selected-window))
+  (let ((old-window (selected-window))

        (old-point (point))
        (old-point (point))

-       (size (and arg (prefix-numeric-value arg)))
-        (window-full-p nil)
-       new-w bottom moved)
-    (and size (< size 0) (setq size (+ (window-height) size)))
-    (setq new-w (split-window nil size))
-    (or split-window-keep-point
-       (progn
-         (save-excursion
-           (set-buffer (window-buffer))
-           (goto-char (window-start))
-            (setq moved (vertical-motion (window-height)))
-           (set-window-start new-w (point))
-           (if (> (point) (window-point new-w))
-               (set-window-point new-w (point)))
-            (and (= moved (window-height))
-                 (progn
-                   (setq window-full-p t)
-                   (vertical-motion -1)))
-            (setq bottom (point)))
-          (and window-full-p
-               (<= bottom (point))
-               (set-window-point old-w (1- bottom)))
-         (and window-full-p
-               (<= (window-start new-w) old-point)
-               (progn
-                 (set-window-point new-w old-point)
-                 (select-window new-w)))))
-    (split-window-save-restore-data new-w old-w)))
+       (size (and size (prefix-numeric-value size)))
+        moved-by-window-height moved new-window bottom)
+    (and size (< size 0)
+        ;; Handle negative SIZE value.
+        (setq size (+ (window-height) size)))
+    (setq new-window (split-window nil size))
+    (unless split-window-keep-point
+      (with-current-buffer (window-buffer)
+       (goto-char (window-start))
+       (setq moved (vertical-motion (window-height)))
+       (set-window-start new-window (point))
+       (when (> (point) (window-point new-window))
+         (set-window-point new-window (point)))
+       (when (= moved (window-height))
+         (setq moved-by-window-height t)
+         (vertical-motion -1))
+       (setq bottom (point)))
+      (and moved-by-window-height
+          (<= bottom (point))
+          (set-window-point old-window (1- bottom)))
+      (and moved-by-window-height
+          (<= (window-start new-window) old-point)
+          (set-window-point new-window old-point)
+          (select-window new-window)))
+    (split-window-save-restore-data new-window old-window)))

 
 ;; This is to avoid compiler warnings.
 (defvar view-return-to-alist)
 
 
 ;; This is to avoid compiler warnings.
 (defvar view-return-to-alist)
 

-(defun split-window-save-restore-data (new-w old-w)
+(defun split-window-save-restore-data (new-window old-window)

   (with-current-buffer (window-buffer)
   (with-current-buffer (window-buffer)

-    (if view-mode
-       (let ((old-info (assq old-w view-return-to-alist)))
-         (if old-info
-             (push (cons new-w (cons (car (cdr old-info)) t))
-                   view-return-to-alist))))
-    new-w))
-
-(defun split-window-horizontally (&optional arg)
-  "Split current window into two windows side by side.
-This window becomes the leftmost of the two, and gets ARG columns.
-Negative ARG means select the size of the rightmost window instead.
-The argument includes the width of the window's scroll bar; if there
-are no scroll bars, it includes the width of the divider column
-to the window's right, if any.  No ARG means split equally.
-
-The original, leftmost window remains selected.
-The return value is the new, rightmost window."
+    (when view-mode
+      (let ((old-info (assq old-window view-return-to-alist)))
+       (when old-info
+         (push (cons new-window (cons (car (cdr old-info)) t))
+               view-return-to-alist))))
+    new-window))
+
+(defun split-window-horizontally (&optional size)
+  "Split selected window into two windows side by side.
+The selected window becomes the left one and gets SIZE columns.
+SIZE negative means the right window gets -SIZE lines.
+
+SIZE includes the width of the window's scroll bar; if there are
+no scroll bars, it includes the width of the divider column to
+the window's right, if any.  SIZE omitted or nil means split
+window equally.
+
+The selected window remains selected.  Return the new window."

   (interactive "P")
   (interactive "P")

-  (let ((old-w (selected-window))
-       (size (and arg (prefix-numeric-value arg))))
+  (let ((old-window (selected-window))
+       (size (and size (prefix-numeric-value size))))

     (and size (< size 0)
     (and size (< size 0)

+        ;; Handle negative SIZE value.

         (setq size (+ (window-width) size)))
         (setq size (+ (window-width) size)))

-    (split-window-save-restore-data (split-window nil size t) old-w)))
+    (split-window-save-restore-data (split-window nil size t) old-window)))

 
 \f
 (defun set-window-text-height (window height)
 
 \f
 (defun set-window-text-height (window height)

-  "Sets the height in lines of the text display area of WINDOW to HEIGHT.
-This doesn't include the mode-line (or header-line if any) or any
-partial-height lines in the text display area.
-
-If WINDOW is nil, the selected window is used.
-
-Note that the current implementation of this function cannot always set
-the height exactly, but attempts to be conservative, by allocating more
-lines than are actually needed in the case where some error may be present."
+  "Set the height in lines of the text display area of WINDOW to HEIGHT.
+HEIGHT doesn't include the mode line or header line, if any, or
+any partial-height lines in the text display area.
+
+Note that the current implementation of this function cannot
+always set the height exactly, but attempts to be conservative,
+by allocating more lines than are actually needed in the case
+where some error may be present."

   (let ((delta (- height (window-text-height window))))
     (unless (zerop delta)
       ;; Setting window-min-height to a value like 1 can lead to very
       ;; bizarre displays because it also allows Emacs to make *other*
       ;; windows 1-line tall, which means that there's no more space for
       ;; the modeline.
   (let ((delta (- height (window-text-height window))))
     (unless (zerop delta)
       ;; Setting window-min-height to a value like 1 can lead to very
       ;; bizarre displays because it also allows Emacs to make *other*
       ;; windows 1-line tall, which means that there's no more space for
       ;; the modeline.

-      (let ((window-min-height (min 2 height))) ;One text line plus a modeline.
+      (let ((window-min-height (min 2 height))) ; One text line plus a modeline.

        (if (and window (not (eq window (selected-window))))
            (save-selected-window
        (if (and window (not (eq window (selected-window))))
            (save-selected-window

-             (select-window window)
+             (select-window window 'norecord)

              (enlarge-window delta))
          (enlarge-window delta))))))
 
 \f
              (enlarge-window delta))
          (enlarge-window delta))))))
 
 \f

-(defun enlarge-window-horizontally (arg)
-  "Make current window ARG columns wider."
+(defun enlarge-window-horizontally (columns)
+  "Make selected window COLUMNS wider.
+Interactively, if no argument is given, make selected window one
+column wider."

   (interactive "p")
   (interactive "p")

-  (enlarge-window arg t))
+  (enlarge-window columns t))

 
 

-(defun shrink-window-horizontally (arg)
-  "Make current window ARG columns narrower."
+(defun shrink-window-horizontally (columns)
+  "Make selected window COLUMNS narrower.
+Interactively, if no argument is given, make selected window one
+column narrower."

   (interactive "p")
   (interactive "p")

-  (shrink-window arg t))
+  (shrink-window columns t))

 
 (defun window-buffer-height (window)
   "Return the height (in screen lines) of the buffer that WINDOW is displaying."
 
 (defun window-buffer-height (window)
   "Return the height (in screen lines) of the buffer that WINDOW is displaying."


@@ -696,96 +1415,129 @@ in some window."
         (1+ (vertical-motion (buffer-size) window))))))
 
 (defun fit-window-to-buffer (&optional window max-height min-height)
         (1+ (vertical-motion (buffer-size) window))))))
 
 (defun fit-window-to-buffer (&optional window max-height min-height)

-  "Make WINDOW the right height to display its contents exactly.
-If WINDOW is omitted or nil, it defaults to the selected window.
-If the optional argument MAX-HEIGHT is supplied, it is the maximum height
-  the window is allowed to be, defaulting to the frame height.
-If the optional argument MIN-HEIGHT is supplied, it is the minimum
-  height the window is allowed to be, defaulting to `window-min-height'.
-
-The heights in MAX-HEIGHT and MIN-HEIGHT include the mode-line and/or
-header-line."
+  "Adjust height of WINDOW to display its buffer's contents exactly.
+WINDOW defaults to the selected window.
+Optional argument MAX-HEIGHT specifies the maximum height of the
+window and defaults to the maximum permissible height of a window
+on WINDOW's frame.
+Optional argument MIN-HEIGHT specifies the minimum height of the
+window and defaults to `window-min-height'.
+Both, MAX-HEIGHT and MIN-HEIGHT are specified in lines and
+include the mode line and header line, if any.
+
+Return non-nil if height was orderly adjusted, nil otherwise.
+
+Caution: This function can delete WINDOW and/or other windows
+when their height shrinks to less than MIN-HEIGHT."

   (interactive)
   (interactive)

+  ;; Do all the work in WINDOW and its buffer and restore the selected
+  ;; window and the current buffer when we're done.
+  (let ((old-buffer (current-buffer))
+       value)
+    (with-selected-window (or window (setq window (selected-window)))
+      (set-buffer (window-buffer))
+      ;; Use `condition-case' to handle any fixed-size windows and other
+      ;; pitfalls nearby.
+      (condition-case nil
+         (let* (;; MIN-HEIGHT must not be less than 1 and defaults to
+                ;; `window-min-height'.
+                (min-height (max (or min-height window-min-height) 1))
+                (max-window-height
+                 ;; Maximum height of any window on this frame.
+                 (min (window-height (frame-root-window)) (frame-height)))
+                ;; MAX-HEIGHT must not be larger than max-window-height and
+                ;; defaults to max-window-height.
+                (max-height
+                 (min (or max-height max-window-height) max-window-height))
+                (desired-height
+                 ;; The height necessary to show all of WINDOW's buffer,
+                 ;; constrained by MIN-HEIGHT and MAX-HEIGHT.
+                 (max
+                  (min
+                   ;; For an empty buffer `count-screen-lines' returns zero.
+                   ;; Even in that case we need one line for the cursor.
+                   (+ (max (count-screen-lines) 1)
+                      ;; For non-minibuffers count the mode line, if any.
+                      (if (and (not (window-minibuffer-p)) mode-line-format)
+                          1 0)
+                      ;; Count the header line, if any.
+                      (if header-line-format 1 0))
+                   max-height)
+                  min-height))
+                (delta
+                 ;; How much the window height has to change.
+                 (if (= (window-height) (window-height (frame-root-window)))
+                     ;; Don't try to resize a full-height window.
+                     0
+                   (- desired-height (window-height))))
+                ;; Do something reasonable so `enlarge-window' can make
+                ;; windows as small as MIN-HEIGHT.
+                (window-min-height (min min-height window-min-height)))
+           ;; Don't try to redisplay with the cursor at the end on its
+           ;; own line--that would force a scroll and spoil things.
+           (when (and (eobp) (bolp) (not (bobp)))
+             (set-window-point window (1- (window-point))))
+           ;; Adjust WINDOW's height to the nominally correct one
+           ;; (which may actually be slightly off because of variable
+           ;; height text, etc).
+           (unless (zerop delta)
+             (enlarge-window delta))
+           ;; `enlarge-window' might have deleted WINDOW, so make sure
+           ;; WINDOW's still alive for the remainder of this.
+           ;; Note: Deleting WINDOW is clearly counter-intuitive in
+           ;; this context, but we can't do much about it given the
+           ;; current semantics of `enlarge-window'.
+           (when (window-live-p window)
+             ;; Check if the last line is surely fully visible.  If
+             ;; not, enlarge the window.
+             (let ((end (save-excursion
+                          (goto-char (point-max))
+                          (when (and (bolp) (not (bobp)))
+                            ;; Don't include final newline.
+                            (backward-char 1))
+                          (when truncate-lines
+                            ;; If line-wrapping is turned off, test the
+                            ;; beginning of the last line for
+                            ;; visibility instead of the end, as the
+                            ;; end of the line could be invisible by
+                            ;; virtue of extending past the edge of the
+                            ;; window.
+                            (forward-line 0))
+                          (point))))
+               (set-window-vscroll window 0)
+               (while (and (< desired-height max-height)
+                           (= desired-height (window-height))
+                           (not (pos-visible-in-window-p end)))
+                 (enlarge-window 1)
+                 (setq desired-height (1+ desired-height))))
+             ;; Return non-nil only if nothing "bad" happened.
+             (setq value t)))
+       (error nil)))
+    (when (buffer-live-p old-buffer)
+      (set-buffer old-buffer))
+    value))

 
 

-  (when (null window)
-    (setq window (selected-window)))
-  (when (null max-height)
-    (setq max-height (frame-height (window-frame window))))
-
-  (let* ((buf
-         ;; Buffer that is displayed in WINDOW
-         (window-buffer window))
-        (window-height
-         ;; The current height of WINDOW
-         (window-height window))
-        (desired-height
-         ;; The height necessary to show the buffer displayed by WINDOW
-         ;; (`count-screen-lines' always works on the current buffer).
-         (with-current-buffer buf
-           (+ (count-screen-lines)
-              ;; If the buffer is empty, (count-screen-lines) is
-              ;; zero.  But, even in that case, we need one text line
-              ;; for cursor.
-              (if (= (point-min) (point-max))
-                  1 0)
-              ;; For non-minibuffers, count the mode-line, if any
-              (if (and (not (window-minibuffer-p window))
-                       mode-line-format)
-                  1 0)
-              ;; Count the header-line, if any
-              (if header-line-format 1 0))))
-        (delta
-         ;; Calculate how much the window height has to change to show
-         ;; desired-height lines, constrained by MIN-HEIGHT and MAX-HEIGHT.
-         (- (max (min desired-height max-height)
-                 (or min-height window-min-height))
-            window-height)))
-
-    ;; Don't try to redisplay with the cursor at the end
-    ;; on its own line--that would force a scroll and spoil things.
-    (when (with-current-buffer buf
-           (and (eobp) (bolp) (not (bobp))))
-      (set-window-point window (1- (window-point window))))
-
-    (save-selected-window
-      (select-window window)
-
-      ;; Adjust WINDOW to the nominally correct size (which may actually
-      ;; be slightly off because of variable height text, etc).
-      (unless (zerop delta)
-       (enlarge-window delta))
-
-      ;; Check if the last line is surely fully visible.  If not,
-      ;; enlarge the window.
-      (let ((end (with-current-buffer buf
-                  (save-excursion
-                    (goto-char (point-max))
-                    (when (and (bolp) (not (bobp)))
-                      ;; Don't include final newline
-                      (backward-char 1))
-                    (when truncate-lines
-                      ;; If line-wrapping is turned off, test the
-                      ;; beginning of the last line for visibility
-                      ;; instead of the end, as the end of the line
-                      ;; could be invisible by virtue of extending past
-                      ;; the edge of the window.
-                      (forward-line 0))
-                    (point)))))
-       (set-window-vscroll window 0)
-       (while (and (< desired-height max-height)
-                   (= desired-height (window-height window))
-                   (not (pos-visible-in-window-p end window)))
-         (enlarge-window 1)
-         (setq desired-height (1+ desired-height)))))))
+(defun window-safely-shrinkable-p (&optional window)
+  "Return t if WINDOW can be shrunk without shrinking other windows.
+WINDOW defaults to the selected window."
+  (with-selected-window (or window (selected-window))
+    (let ((edges (window-edges)))
+      (or (= (nth 2 edges) (nth 2 (window-edges (previous-window))))
+         (= (nth 0 edges) (nth 0 (window-edges (next-window))))))))

 
 (defun shrink-window-if-larger-than-buffer (&optional window)
 
 (defun shrink-window-if-larger-than-buffer (&optional window)

-  "Shrink the WINDOW to be as small as possible to display its contents.
-If WINDOW is omitted or nil, it defaults to the selected window.
-Do not shrink to less than `window-min-height' lines.
-Do nothing if the buffer contains more lines than the present window height,
-or if some of the window's contents are scrolled out of view,
-or if shrinking this window would also shrink another window,
-or if the window is the only window of its frame."
+  "Shrink height of WINDOW if its buffer doesn't need so many lines.
+More precisely, shrink WINDOW vertically to be as small as
+possible, while still showing the full contents of its buffer.
+WINDOW defaults to the selected window.
+
+Do not shrink to less than `window-min-height' lines.  Do nothing
+if the buffer contains more lines than the present window height,
+or if some of the window's contents are scrolled out of view, or
+if shrinking this window would also shrink another window, or if
+the window is the only window of its frame.
+
+Return non-nil if the window was shrunk, nil otherwise."

   (interactive)
   (when (null window)
     (setq window (selected-window)))
   (interactive)
   (when (null window)
     (setq window (selected-window)))


@@ -793,7 +1545,7 @@ or if the window is the only window of its frame."
         (mini (frame-parameter frame 'minibuffer))
         (edges (window-edges window)))
     (if (and (not (eq window (frame-root-window frame)))
         (mini (frame-parameter frame 'minibuffer))
         (edges (window-edges window)))
     (if (and (not (eq window (frame-root-window frame)))

-            (window-safely-shrinkable-p)
+            (window-safely-shrinkable-p window)

             (pos-visible-in-window-p (point-min) window)
             (not (eq mini 'only))
             (or (not mini)
             (pos-visible-in-window-p (point-min) window)
             (not (eq mini 'only))
             (or (not mini)


@@ -831,89 +1583,131 @@ or if the window is the only window of its frame."
        (error nil)))))
 
 (defun quit-window (&optional kill window)
        (error nil)))))
 
 (defun quit-window (&optional kill window)

-  "Quit the current buffer.  Bury it, and maybe delete the selected frame.
-\(The frame is deleted if it contains a dedicated window for the buffer.)
-With a prefix argument, kill the buffer instead.
+  "Quit WINDOW and bury its buffer.
+With a prefix argument, kill the buffer instead.  WINDOW defaults
+to the selected window.

 
 

-Noninteractively, if KILL is non-nil, then kill the current buffer,
-otherwise bury it.
+If WINDOW is non-nil, dedicated, or a minibuffer window, delete
+it and, if it's alone on its frame, its frame too.  Otherwise, or
+if deleting WINDOW fails in any of the preceding cases, display
+another buffer in WINDOW using `switch-to-buffer'.

 
 

-If WINDOW is non-nil, it specifies a window; we delete that window,
-and the buffer that is killed or buried is the one in that window."
+Optional argument KILL non-nil means kill WINDOW's buffer.
+Otherwise, bury WINDOW's buffer, see `bury-buffer'."

   (interactive "P")
   (interactive "P")

-  (let ((buffer (window-buffer window))
-       (frame (window-frame (or window (selected-window))))
-       (window-solitary
-        (save-selected-window
-          (if window
-              (select-window window))
-          (one-window-p t)))
-       window-handled)
-
-    (save-selected-window
-      (if window
-         (select-window window))
-      (or (window-minibuffer-p)
-         (window-dedicated-p (selected-window))
-         (switch-to-buffer (other-buffer))))
-
-    ;; Get rid of the frame, if it has just one dedicated window
-    ;; and other visible frames exist.
-    (and (or (window-minibuffer-p) (window-dedicated-p window))
-        (delq frame (visible-frame-list))
-        window-solitary
-        (if (and (eq default-minibuffer-frame frame)
-                 (= 1 (length (minibuffer-frame-list))))
-            (setq window nil)
-          (delete-frame frame)
-          (setq window-handled t)))
+  (let ((buffer (window-buffer window)))
+    (if (or window
+           (window-minibuffer-p window)
+           (window-dedicated-p window))
+       ;; WINDOW is either non-nil, a minibuffer window, or dedicated;
+       ;; try to delete it.
+       (let* ((window (or window (selected-window)))
+              (frame (window-frame window)))
+         (if (eq window (frame-root-window frame))
+             ;; WINDOW is alone on its frame.  `delete-windows-on'
+             ;; knows how to handle that case.
+             (delete-windows-on buffer frame)
+           ;; There are other windows on its frame, delete WINDOW.
+           (delete-window window)))
+      ;; Otherwise, switch to another buffer in the selected window.
+      (switch-to-buffer nil))

 
     ;; Deal with the buffer.
     (if kill
        (kill-buffer buffer)
 
     ;; Deal with the buffer.
     (if kill
        (kill-buffer buffer)

-      (bury-buffer buffer))
-
-    ;; Maybe get rid of the window.
-    (and window (not window-handled) (not window-solitary)
-        (delete-window window))))
+      (bury-buffer buffer))))

 
 (defvar recenter-last-op nil
   "Indicates the last recenter operation performed.
 
 (defvar recenter-last-op nil
   "Indicates the last recenter operation performed.

-Possible values: `top', `middle', `bottom'.")
+Possible values: `top', `middle', `bottom', integer or float numbers.")
+
+(defcustom recenter-positions '(middle top bottom)
+  "Cycling order for `recenter-top-bottom'.
+A list of elements with possible values `top', `middle', `bottom',
+integer or float numbers that define the cycling order for
+the command `recenter-top-bottom'.
+
+Top and bottom destinations are `scroll-margin' lines the from true
+window top and bottom.  Middle redraws the frame and centers point
+vertically within the window.  Integer number moves current line to
+the specified absolute window-line.  Float number between 0.0 and 1.0
+means the percentage of the screen space from the top.  The default
+cycling order is middle -> top -> bottom."
+  :type '(repeat (choice
+                 (const :tag "Top" top)
+                 (const :tag "Middle" middle)
+                 (const :tag "Bottom" bottom)
+                 (integer :tag "Line number")
+                 (float :tag "Percentage")))
+  :version "23.2"
+  :group 'windows)

 
 (defun recenter-top-bottom (&optional arg)
 
 (defun recenter-top-bottom (&optional arg)

-  "Move current line to window center, top, and bottom, successively.
-With a prefix argument, this is the same as `recenter':
+  "Move current buffer line to the specified window line.
+With no prefix argument, successive calls place point according
+to the cycling order defined by `recenter-positions'.
+
+A prefix argument is handled like `recenter':

  With numeric prefix ARG, move current line to window-line ARG.
  With numeric prefix ARG, move current line to window-line ARG.

- With plain `C-u', move current line to window center.
+ With plain `C-u', move current line to window center."
+  (interactive "P")
+  (cond
+   (arg (recenter arg))                        ; Always respect ARG.
+   (t
+    (setq recenter-last-op
+         (if (eq this-command last-command)
+             (car (or (cdr (member recenter-last-op recenter-positions))
+                      recenter-positions))
+           (car recenter-positions)))
+    (let ((this-scroll-margin
+          (min (max 0 scroll-margin)
+               (truncate (/ (window-body-height) 4.0)))))
+      (cond ((eq recenter-last-op 'middle)
+            (recenter))
+           ((eq recenter-last-op 'top)
+            (recenter this-scroll-margin))
+           ((eq recenter-last-op 'bottom)
+            (recenter (- -1 this-scroll-margin)))
+           ((integerp recenter-last-op)
+            (recenter recenter-last-op))
+           ((floatp recenter-last-op)
+            (recenter (round (* recenter-last-op (window-height))))))))))
+
+(define-key global-map [?\C-l] 'recenter-top-bottom)

 
 

-Otherwise move current line to window center on first call, and to
-top, middle, or bottom on successive calls.
+(defun move-to-window-line-top-bottom (&optional arg)
+  "Position point relative to window.

 
 

-The cycling order is: middle -> top -> bottom.
+With a prefix argument ARG, acts like `move-to-window-line'.

 
 

-Top and bottom destinations are actually `scroll-conservatively' lines
-from true window top and bottom."
+With no argument, positions point at center of window.
+Successive calls position point at positions defined
+by `recenter-positions'."

   (interactive "P")
   (cond
   (interactive "P")
   (cond

-   (arg (recenter arg))                 ; Always respect ARG.
-   ((not (eq this-command last-command))
-    ;; First time - save mode and recenter.
-    (setq recenter-last-op 'middle)
-    (recenter))
-   (t ;; repeat: loop through various options.
+   (arg (move-to-window-line arg))     ; Always respect ARG.
+   (t

     (setq recenter-last-op
     (setq recenter-last-op

-         (cond ((eq recenter-last-op 'middle)
-                (recenter scroll-conservatively)
-                'top)
-               ((eq recenter-last-op 'top)
-                (recenter (1- (- scroll-conservatively)))
-                'bottom)
-               ((eq recenter-last-op 'bottom)
-                (recenter)
-                'middle))))))
+         (if (eq this-command last-command)
+             (car (or (cdr (member recenter-last-op recenter-positions))
+                      recenter-positions))
+           (car recenter-positions)))
+    (let ((this-scroll-margin
+          (min (max 0 scroll-margin)
+               (truncate (/ (window-body-height) 4.0)))))
+      (cond ((eq recenter-last-op 'middle)
+            (call-interactively 'move-to-window-line))
+           ((eq recenter-last-op 'top)
+            (move-to-window-line this-scroll-margin))
+           ((eq recenter-last-op 'bottom)
+            (move-to-window-line (- -1 this-scroll-margin)))
+           ((integerp recenter-last-op)
+            (move-to-window-line recenter-last-op))
+           ((floatp recenter-last-op)
+            (move-to-window-line (round (* recenter-last-op (window-height))))))))))
+
+(define-key global-map [?\M-r] 'move-to-window-line-top-bottom)

 
 

-(define-key global-map [?\C-l] 'recenter-top-bottom)

 \f
 (defvar mouse-autoselect-window-timer nil
   "Timer used by delayed window autoselection.")
 \f
 (defvar mouse-autoselect-window-timer nil
   "Timer used by delayed window autoselection.")


@@ -1045,8 +1839,8 @@ active.  This function is run by `mouse-autoselect-window-timer'."
                     (progn
                       ;; Cancel any delayed autoselection.
                       (mouse-autoselect-window-cancel t)
                     (progn
                       ;; Cancel any delayed autoselection.
                       (mouse-autoselect-window-cancel t)

-                      ;; Start delayed autoselection from current mouse position
-                      ;; and window.
+                      ;; Start delayed autoselection from current mouse
+                      ;; position and window.

                       (mouse-autoselect-window-start (mouse-position) window)
                       ;; Executing a command cancels delayed autoselection.
                       (add-hook
                       (mouse-autoselect-window-start (mouse-position) window)
                       ;; Executing a command cancels delayed autoselection.
                       (add-hook


@@ -1058,6 +1852,37 @@ active.  This function is run by `mouse-autoselect-window-timer'."
        (run-hooks 'mouse-leave-buffer-hook))
       (select-window window))))
 
        (run-hooks 'mouse-leave-buffer-hook))
       (select-window window))))
 

+(defun delete-other-windows-vertically (&optional window)
+  "Delete the windows in the same column with WINDOW, but not WINDOW itself.
+This may be a useful alternative binding for \\[delete-other-windows]
+ if you often split windows horizontally."
+  (interactive)
+  (let* ((window (or window (selected-window)))
+         (edges (window-edges window))
+         (w window) delenda)
+    (while (not (eq (setq w (next-window w 1)) window))
+      (let ((e (window-edges w)))
+        (when (and (= (car e) (car edges))
+                   (= (caddr e) (caddr edges)))
+          (push w delenda))))
+    (mapc 'delete-window delenda)))
+
+(defun truncated-partial-width-window-p (&optional window)
+  "Return non-nil if lines in WINDOW are specifically truncated due to its width.
+WINDOW defaults to the selected window.
+Return nil if WINDOW is not a partial-width window
+ (regardless of the value of `truncate-lines').
+Otherwise, consult the value of `truncate-partial-width-windows'
+ for the buffer shown in WINDOW."
+  (unless window
+    (setq window (selected-window)))
+  (unless (window-full-width-p window)
+    (let ((t-p-w-w (buffer-local-value 'truncate-partial-width-windows
+                                      (window-buffer window))))
+      (if (integerp t-p-w-w)
+         (< (window-width window) t-p-w-w)
+       t-p-w-w))))
+

 (define-key ctl-x-map "2" 'split-window-vertically)
 (define-key ctl-x-map "3" 'split-window-horizontally)
 (define-key ctl-x-map "}" 'enlarge-window-horizontally)
 (define-key ctl-x-map "2" 'split-window-vertically)
 (define-key ctl-x-map "3" 'split-window-horizontally)
 (define-key ctl-x-map "}" 'enlarge-window-horizontally)