Don't delete frame when there's a previous buffer to show (Bug#9419).

* window.el (window-deletable-p): Don't return a non-nil value
when there's a buffer that was shown in the window before.
(Bug#9419)
(display-buffer-pop-up-frame, display-buffer-pop-up-window): Set
window's previous buffers to nil.

2 files changed, 43 insertions, 13 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 781833d309c..a365d6078ea 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2011-09-03  Martin Rudalics  <rudalics@gmx.at>
+
+        * window.el (window-deletable-p): Don't return a non-nil value
+        when there's a buffer that was shown in the window before.
+        (Bug#9419)
+        (display-buffer-pop-up-frame, display-buffer-pop-up-window): Set
+        window's previous buffers to nil.
+
 2011-09-03  Eli Zaretskii  <eliz@gnu.org>
 
         * mail/rmailmm.el (rmail-mime-insert-tagline): Insert an extra
diff --git a/lisp/window.el b/lisp/window.el
index d078fbec35d..5272841a9c7 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -2291,29 +2291,45 @@ frame."
       (setq window (window-atom-root window))))
   (let ((parent (window-parent window))
         (frame (window-frame window))
+        (buffer (window-buffer window))
         (dedicated (and (window-buffer window) (window-dedicated-p window)))
         (quit-restore (window-parameter window 'quit-restore)))
     (cond
      ((frame-root-window-p window)
+     ;; Don't delete FRAME if `frame-auto-delete' is nil.
       (when (and (or (eq frame-auto-delete t)
                      (and (eq frame-auto-delete 'automatic)
+                          ;; Delete FRAME only if it's either dedicated
+                          ;; or quit-restore's car is `new-frame' and
+                          ;; WINDOW still displays the same buffer
                           (or dedicated
                               (and (eq (car-safe quit-restore) 'new-frame)
                                    (eq (nth 1 quit-restore)
                                        (window-buffer window))))))
+                 ;; Don't delete FRAME if we have another buffer in
+                 ;; WINDOW's previous buffers.  Bug#9419.
+                 (or (not (window-prev-buffers window))
+                     (eq (caar (window-prev-buffers window)) buffer))
+                 ;; Don't try to delete FRAME when there are no other
+                 ;; visible frames left.
                  (other-visible-frames-p frame))
-        ;; WINDOW is the root window of its frame.  Return `frame' but
-        ;; only if WINDOW is (1) either dedicated or quit-restore's car
-        ;; is `new-frame' and the window still displays the same buffer
-        ;; and (2) there are other frames left.
         'frame))
-     ((and (not ignore-window-parameters)
-           (eq (window-parameter window 'window-side) 'none)
-           (or (not parent)
-               (not (eq (window-parameter parent 'window-side) 'none))))
-      ;; Can't delete last main window.
-      nil)
-     (t))))
+     ;; Don't delete WINDOW if we find another buffer in WINDOW's
+     ;; previous buffers.
+     ((and (or (not (window-prev-buffers window))
+               (eq (caar (window-prev-buffers window)) buffer))
+           ;; Delete WINDOW only if it's dedicated or quit-restore's car
+           ;; is `new-frame' or `new-window' and it still displays the
+           ;; same buffer.
+           (or dedicated
+               (and (memq (car-safe quit-restore) '(new-window new-frame))
+                    (eq (nth 1 quit-restore) (window-buffer window))))
+           ;; Don't delete the last main window.
+           (or ignore-window-parameters
+               (not (eq (window-parameter window 'window-side) 'none))
+               (and parent
+                    (eq (window-parameter parent 'window-side) 'none))))
+      t))))
 
 (defun window-or-subwindow-p (subwindow window)
   "Return t if SUBWINDOW is either WINDOW or a subwindow of WINDOW."
@@ -4714,7 +4730,10 @@ return the window on the new frame; otherwise return nil."
                (setq frame (funcall fun))
                (setq window (frame-selected-window frame)))
       (display-buffer-record-window 'pop-up-frame window buffer)
-      (window--display-buffer-2 buffer window))))
+      (window--display-buffer-2 buffer window)
+      ;; Reset list of WINDOW's previous buffers to nil.
+      (set-window-prev-buffers window nil)
+      window)))
 
 (defun display-buffer-pop-up-window (buffer alist)
   "Display BUFFER by popping up a new window.
@@ -4737,7 +4756,10 @@ If sucessful, return the new window; otherwise return nil."
                                 (window--try-to-split-window
                                  (get-lru-window frame t)))))
       (display-buffer-record-window 'pop-up-window window buffer)
-      (window--display-buffer-2 buffer window))))
+      (window--display-buffer-2 buffer window)
+      ;; Reset list of WINDOW's previous buffers to nil.
+      (set-window-prev-buffers window nil)
+      window)))
 
 ;; This display action function groups together some lower-level ones:
 (defun display-buffer-reuse-or-pop-window (buffer alist)