alps-adjusted.patch

=== modified file 'lisp/window.el'
--- lisp/window.el      2012-07-18 10:02:54 +0000
+++ lisp/window.el      2012-07-29 16:59:18 +0000
@@ -2656,10 +2656,12 @@
         (old-buffer (window-buffer window))
         ;; Save this since it's destroyed by `set-window-buffer'.
         (next-buffers (window-next-buffers window))
+         (pred (frame-parameter frame 'buffer-predicate))
         entry new-buffer killed-buffers visible)
     (when (window-dedicated-p window)
       (error "Window %s is dedicated to buffer %s" window old-buffer))

+    (unless
     (catch 'found
       ;; Scan WINDOW's previous buffers first, skipping entries of next
       ;; buffers.
@@ -2669,6 +2671,7 @@
                       (not (setq killed-buffers
                                  (cons new-buffer killed-buffers))))
                   (not (eq new-buffer old-buffer))
+                   (or (null pred) (funcall pred new-buffer))
                    (or bury-or-kill
                       (not (memq new-buffer next-buffers))))
          (if (and (not switch-to-visible-buffer)
@@ -2690,6 +2693,7 @@
        (when (and (buffer-live-p buffer)
                   (not (eq buffer old-buffer))
                   (not (eq (aref (buffer-name buffer) 0) ?\s))
+                   (or (null pred) (funcall pred buffer))
                   (or bury-or-kill (not (memq buffer next-buffers))))
          (if (get-buffer-window buffer frame)
              ;; Try to avoid showing a buffer visible in some other window.
@@ -2708,16 +2712,22 @@
                         (not (setq killed-buffers
                                    (cons buffer killed-buffers))))
                     (not (eq buffer old-buffer))
+                     (or (null pred) (funcall pred buffer))
                     (setq entry (assq buffer (window-prev-buffers window))))
            (setq new-buffer buffer)
            (set-window-buffer-start-and-point
             window new-buffer (nth 1 entry) (nth 2 entry))
-           (throw 'found t))))
-
-      ;; Show a buffer visible in another window.
-      (when visible
-       (setq new-buffer visible)
-       (set-window-buffer-start-and-point window new-buffer)))
+           (throw 'found t)))))
+
+      ;; If we reach this, then either: (1) we have a
+      ;; candidate buffer that was skipped because it was already visible on
+      ;; the frame, in which case we switch to it now, or (2) no candidate
+      ;; was found, in which case we switch to *scratch*.
+      (if visible
+          (setq new-buffer visible)
+        (setq new-buffer (get-buffer-create "*scratch*")))
+      (set-window-buffer-start-and-point window new-buffer))
+

     (if bury-or-kill
        ;; Remove `old-buffer' from WINDOW's previous and (restored list
@@ -2750,10 +2760,12 @@
         (frame (window-frame window))
         (old-buffer (window-buffer window))
         (next-buffers (window-next-buffers window))
+         (pred (frame-parameter frame 'buffer-predicate))
         new-buffer entry killed-buffers visible)
     (when (window-dedicated-p window)
       (error "Window %s is dedicated to buffer %s" window old-buffer))

+    (unless
     (catch 'found
       ;; Scan WINDOW's next buffers first.
       (dolist (buffer next-buffers)
@@ -2761,6 +2772,7 @@
                       (not (setq killed-buffers
                                  (cons buffer killed-buffers))))
                   (not (eq buffer old-buffer))
+                   (or (null pred) (funcall pred buffer))
                   (setq entry (assq buffer (window-prev-buffers window))))
          (setq new-buffer buffer)
          (set-window-buffer-start-and-point
@@ -2771,6 +2783,7 @@
       (dolist (buffer (buffer-list frame))
        (when (and (buffer-live-p buffer) (not (eq buffer old-buffer))
                   (not (eq (aref (buffer-name buffer) 0) ?\s))
+                   (or (null pred) (funcall pred buffer))
                   (not (assq buffer (window-prev-buffers window))))
          (if (get-buffer-window buffer frame)
              ;; Try to avoid showing a buffer visible in some other window.
@@ -2785,6 +2798,7 @@
                   (or (buffer-live-p new-buffer)
                       (not (setq killed-buffers
                                  (cons new-buffer killed-buffers))))
+                   (or (null pred) (funcall pred new-buffer))
                   (not (eq new-buffer old-buffer)))
          (if (and (not switch-to-visible-buffer)
                   (get-buffer-window new-buffer frame))
@@ -2793,12 +2807,17 @@
                (setq visible new-buffer))
            (set-window-buffer-start-and-point
             window new-buffer (nth 1 entry) (nth 2 entry))
-           (throw 'found t))))
-
-      ;; Show a buffer visible in another window.
-      (when visible
-       (setq new-buffer visible)
-       (set-window-buffer-start-and-point window new-buffer)))
+           (throw 'found t)))))
+
+      ;; If we reach this, then either: (1) we have a candidate buffer that
+      ;; was skipped because it was already visible on the frame, in which
+      ;; case we switch to it now, or (2) no candidate was found, in which
+      ;; case we switch to *scratch*.
+      (if visible
+          (setq new-buffer visible)
+        (setq new-buffer (get-buffer-create "*scratch*")))
+      (set-window-buffer-start-and-point window new-buffer))
+

     ;; Remove `new-buffer' from and restore WINDOW's next buffers.
     (set-window-next-buffers window (delq new-buffer next-buffers))