Merge from trunk.

7 files changed, 420 insertions, 317 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c9c739dde9a..1d5e3f2ddbd 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,7 @@
 2011-06-06  Paul Eggert  <eggert@cs.ucla.edu>
 
+        Integer overflow fixes.
+
         Check for overflow when converting integer to cons and back.
         * charset.c (Fdefine_charset_internal, Fdecode_char):
         Use cons_to_unsigned to catch overflow.
@@ -75,6 +77,52 @@
         (access_keymap): NATNUMP -> INTEGERP, since the integer must be
         nonnegative.
 
+2011-06-06  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * window.h (Fwindow_frame): Declare.
+
+2011-06-06  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * alloc.c: Simplify handling of large-request failures (Bug#8800).
+        (SPARE_MEMORY): Always define.
+        (LARGE_REQUEST): Remove.
+        (memory_full): Use SPARE_MEMORY rather than LARGE_REQUEST.
+
+2011-06-06  Martin Rudalics  <rudalics@gmx.at>
+
+        * lisp.h: Move EXFUNS for Fframe_root_window,
+        Fframe_first_window and Fset_frame_selected_window to window.h.
+
+        * window.h: Move EXFUNS for Fframe_root_window,
+        Fframe_first_window and Fset_frame_selected_window here from
+        lisp.h.
+
+        * frame.c (Fwindow_frame, Fframe_first_window)
+        (Fframe_root_window, Fframe_selected_window)
+        (Fset_frame_selected_window): Move to window.c.
+        (Factive_minibuffer_window): Move to minibuf.c.
+        (Fother_visible_frames_p): New function.
+
+        * minibuf.c (Factive_minibuffer_window): Move here from frame.c.
+
+        * window.c (decode_window, decode_any_window): Move up in code.
+        (Fwindowp, Fwindow_live_p): Rewrite doc-strings.
+        (inhibit_frame_unsplittable): Remove unused variable.
+        (Fwindow_buffer): Move up and rewrite doc-string.
+        (Fwindow_parent, Fwindow_vchild, Fwindow_hchild, Fwindow_next)
+        (Fwindow_prev): New functions.
+        (Fwindow_frame): Move here from frame.c.  Accept any window as
+        argument.
+        (Fframe_root_window, Fframe_first_window)
+        (Fframe_selected_window): Move here from frame.c.  Accept frame
+        or arbitrary window as argument.  Update doc-strings.
+        (Fminibuffer_window): Move up in code.
+        (Fwindow_minibuffer_p): Move up in code and simplify.
+        (Fset_frame_selected_window): Move here from frame.c.
+        Marginal rewrite.
+        (Fselected_window, select_window, Fselect_window): Move up in
+        code.  Minor doc-string fixes.
+
 2011-06-06  Paul Eggert  <eggert@cs.ucla.edu>
 
         * alloc.c (memory_full) [SYSTEM_MALLOC]: Port to MacOS (Bug#8800).
@@ -110,8 +158,8 @@
 
         * xselect.c (x_clipboard_manager_save): Remove redundant arg.
         (x_clipboard_manager_save): Add return value.
-        (x_clipboard_manager_error_1, x_clipboard_manager_error_2): New
-        error handlers.
+        (x_clipboard_manager_error_1, x_clipboard_manager_error_2):
+        New error handlers.
         (x_clipboard_manager_save_frame, x_clipboard_manager_save_all):
         Obey Vx_select_enable_clipboard_manager.  Catch errors in
         x_clipboard_manager_save (Bug#8779).
@@ -139,8 +187,8 @@
         (bidi_fetch_char, bidi_fetch_char_advance): New functions.
         (bidi_cache_search, bidi_cache_iterator_state)
         (bidi_paragraph_init, bidi_resolve_explicit, bidi_resolve_weak)
-        (bidi_level_of_next_char, bidi_move_to_visually_next): Support
-        character positions inside a run of characters covered by a
+        (bidi_level_of_next_char, bidi_move_to_visually_next):
+        Support character positions inside a run of characters covered by a
         display string.
         (bidi_paragraph_init, bidi_resolve_explicit_1)
         (bidi_level_of_next_char): Call bidi_fetch_char and
@@ -151,8 +199,8 @@
         definitions.
         (bidi_explicit_dir_char): Lookup character type in bidi_type_table,
         instead of using explicit *_CHAR codes.
-        (bidi_resolve_explicit, bidi_resolve_weak): Use
-        FETCH_MULTIBYTE_CHAR instead of FETCH_CHAR, as reordering of
+        (bidi_resolve_explicit, bidi_resolve_weak):
+        Use FETCH_MULTIBYTE_CHAR instead of FETCH_CHAR, as reordering of
         bidirectional text is supported only in multibyte buffers.
         (bidi_init_it): Accept additional argument FRAME_WINDOW_P and use
         it to initialize the frame_window_p member of struct bidi_it.
@@ -170,8 +218,8 @@
         (single_display_spec_intangible_p): Function deleted.
         (display_prop_intangible_p): Reimplement to call
         handle_display_spec instead of single_display_spec_intangible_p.
-        Accept 3 additional arguments needed by handle_display_spec.  This
-        fixes incorrect cursor motion across display property with complex
+        Accept 3 additional arguments needed by handle_display_spec.
+        This fixes incorrect cursor motion across display property with complex
         values: lists, `(when COND...)' forms, etc.
         (single_display_spec_string_p): Support property values that are
         lists with the argument STRING its top-level element.
@@ -188,8 +236,8 @@
         the display property will replace the characters it covers.
         (Fcurrent_bidi_paragraph_direction): Initialize the nchars and
         frame_window_p members of struct bidi_it.
-        (compute_display_string_pos, compute_display_string_end): New
-        functions.
+        (compute_display_string_pos, compute_display_string_end):
+        New functions.
         (push_it): Accept second argument POSITION, where pop_it should
         jump to continue iteration.
         (reseat_1): Initialize bidi_it.disp_pos.
@@ -200,8 +248,8 @@
         * dispextern.h (struct bidi_it): New member frame_window_p.
         (bidi_init_it): Update prototypes.
         (display_prop_intangible_p): Update prototype.
-        (compute_display_string_pos, compute_display_string_end): Declare
-        prototypes.
+        (compute_display_string_pos, compute_display_string_end):
+        Declare prototypes.
         (struct bidi_it): New members nchars and disp_pos.  ch_len is now
         EMACS_INT.
 
diff --git a/src/alloc.c b/src/alloc.c
index d9e00c3aeb4..cfbb79b2e61 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -190,17 +190,10 @@ static int total_free_floats, total_floats;
 
 static char *spare_memory[7];
 
-#ifndef SYSTEM_MALLOC
-/* Amount of spare memory to keep in large reserve block.  */
+/* Amount of spare memory to keep in large reserve block, or to see
+   whether this much is available when malloc fails on a larger request.  */
 
 #define SPARE_MEMORY (1 << 14)
-#endif
-
-#ifdef SYSTEM_MALLOC
-# define LARGE_REQUEST (1 << 14)
-#else
-# define LARGE_REQUEST SPARE_MEMORY
-#endif
 
 /* Number of extra blocks malloc should get when it needs more core.  */
 
@@ -3289,9 +3282,9 @@ memory_full (size_t nbytes)
 {
   /* Do not go into hysterics merely because a large request failed.  */
   int enough_free_memory = 0;
-  if (LARGE_REQUEST < nbytes)
+  if (SPARE_MEMORY < nbytes)
     {
-      void *p = malloc (LARGE_REQUEST);
+      void *p = malloc (SPARE_MEMORY);
       if (p)
         {
           free (p);
diff --git a/src/frame.c b/src/frame.c
index 6008ba9567a..68984a68d52 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -904,111 +904,6 @@ DEFUN ("selected-frame", Fselected_frame, Sselected_frame, 0, 0, 0,
   return selected_frame;
 }
 
-DEFUN ("window-frame", Fwindow_frame, Swindow_frame, 1, 1, 0,
-       doc: /* Return the frame object that window WINDOW is on.  */)
-  (Lisp_Object window)
-{
-  CHECK_LIVE_WINDOW (window);
-  return XWINDOW (window)->frame;
-}
-
-DEFUN ("frame-first-window", Fframe_first_window, Sframe_first_window, 0, 1, 0,
-       doc: /* Returns the topmost, leftmost window of FRAME.
-If omitted, FRAME defaults to the currently selected frame.  */)
-  (Lisp_Object frame)
-{
-  Lisp_Object w;
-
-  if (NILP (frame))
-    w = SELECTED_FRAME ()->root_window;
-  else
-    {
-      CHECK_LIVE_FRAME (frame);
-      w = XFRAME (frame)->root_window;
-    }
-  while (NILP (XWINDOW (w)->buffer))
-    {
-      if (! NILP (XWINDOW (w)->hchild))
-        w = XWINDOW (w)->hchild;
-      else if (! NILP (XWINDOW (w)->vchild))
-        w = XWINDOW (w)->vchild;
-      else
-        abort ();
-    }
-  return w;
-}
-
-DEFUN ("active-minibuffer-window", Factive_minibuffer_window,
-       Sactive_minibuffer_window, 0, 0, 0,
-       doc: /* Return the currently active minibuffer window, or nil if none.  */)
-  (void)
-{
-  return minibuf_level ? minibuf_window : Qnil;
-}
-
-DEFUN ("frame-root-window", Fframe_root_window, Sframe_root_window, 0, 1, 0,
-       doc: /* Returns the root-window of FRAME.
-If omitted, FRAME defaults to the currently selected frame.  */)
-  (Lisp_Object frame)
-{
-  Lisp_Object window;
-
-  if (NILP (frame))
-    window = SELECTED_FRAME ()->root_window;
-  else
-    {
-      CHECK_LIVE_FRAME (frame);
-      window = XFRAME (frame)->root_window;
-    }
-
-  return window;
-}
-
-DEFUN ("frame-selected-window", Fframe_selected_window,
-       Sframe_selected_window, 0, 1, 0,
-       doc: /* Return the selected window of FRAME.
-FRAME defaults to the currently selected frame.  */)
-  (Lisp_Object frame)
-{
-  Lisp_Object window;
-
-  if (NILP (frame))
-    window = SELECTED_FRAME ()->selected_window;
-  else
-    {
-      CHECK_LIVE_FRAME (frame);
-      window = XFRAME (frame)->selected_window;
-    }
-
-  return window;
-}
-
-DEFUN ("set-frame-selected-window", Fset_frame_selected_window,
-       Sset_frame_selected_window, 2, 3, 0,
-       doc: /* Set selected window of FRAME to WINDOW.
-If FRAME is nil, use the selected frame.  If FRAME is the
-selected frame, this makes WINDOW the selected window.
-Optional argument NORECORD non-nil means to neither change the
-order of recently selected windows nor the buffer list.
-Return WINDOW.  */)
-  (Lisp_Object frame, Lisp_Object window, Lisp_Object norecord)
-{
-  if (NILP (frame))
-    frame = selected_frame;
-
-  CHECK_LIVE_FRAME (frame);
-  CHECK_LIVE_WINDOW (window);
-
-  if (! EQ (frame, WINDOW_FRAME (XWINDOW (window))))
-    error ("In `set-frame-selected-window', WINDOW is not on FRAME");
-
-  if (EQ (frame, selected_frame))
-    return Fselect_window (window, norecord);
-
-  return XFRAME (frame)->selected_window = window;
-}
-
-
 DEFUN ("frame-list", Fframe_list, Sframe_list,
        0, 0, 0,
        doc: /* Return a list of all live frames.  */)
@@ -1265,6 +1160,17 @@ other_visible_frames (FRAME_PTR f)
   return 1;
 }
 
+DEFUN ("other-visible-frames-p", Fother_visible_frames_p, Sother_visible_frames_p, 0, 1, 0,
+       doc: /* Return t if there are other visible frames beside FRAME.
+FRAME defaults to the selected frame.  */)
+  (Lisp_Object frame)
+{
+  if (NILP (frame))
+    frame = selected_frame;
+  CHECK_LIVE_FRAME (frame);
+  return other_visible_frames (XFRAME (frame)) ? Qt : Qnil;
+}
+
 /* Delete FRAME.  When FORCE equals Qnoelisp, delete FRAME
   unconditionally.  x_connection_closed and delete_terminal use
   this.  Any other value of FORCE implements the semantics
@@ -4605,7 +4511,6 @@ automatically.  See also `mouse-autoselect-window'.  */);
 
   staticpro (&Vframe_list);
 
-  defsubr (&Sactive_minibuffer_window);
   defsubr (&Sframep);
   defsubr (&Sframe_live_p);
   defsubr (&Swindow_system);
@@ -4613,14 +4518,10 @@ automatically.  See also `mouse-autoselect-window'.  */);
   defsubr (&Shandle_switch_frame);
   defsubr (&Sselect_frame);
   defsubr (&Sselected_frame);
-  defsubr (&Swindow_frame);
-  defsubr (&Sframe_root_window);
-  defsubr (&Sframe_first_window);
-  defsubr (&Sframe_selected_window);
-  defsubr (&Sset_frame_selected_window);
   defsubr (&Sframe_list);
   defsubr (&Snext_frame);
   defsubr (&Sprevious_frame);
+  defsubr (&Sother_visible_frames_p);
   defsubr (&Sdelete_frame);
   defsubr (&Smouse_position);
   defsubr (&Smouse_pixel_position);
diff --git a/src/lisp.h b/src/lisp.h
index 1c1e3ec3708..c5f810a0746 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3215,16 +3215,12 @@ extern Lisp_Object get_frame_param (struct frame *, Lisp_Object);
 extern Lisp_Object frame_buffer_predicate (Lisp_Object);
 EXFUN (Fselect_frame, 2);
 EXFUN (Fselected_frame, 0);
-EXFUN (Fwindow_frame, 1);
-EXFUN (Fframe_root_window, 1);
-EXFUN (Fframe_first_window, 1);
 EXFUN (Fmake_frame_visible, 1);
 EXFUN (Ficonify_frame, 1);
 EXFUN (Fframe_parameter, 2);
 EXFUN (Fmodify_frame_parameters, 2);
 EXFUN (Fraise_frame, 1);
 EXFUN (Fredirect_frame_focus, 2);
-EXFUN (Fset_frame_selected_window, 3);
 extern Lisp_Object frame_buffer_list (Lisp_Object);
 extern void frames_discard_buffer (Lisp_Object);
 extern void set_frame_buffer_list (Lisp_Object, Lisp_Object);
diff --git a/src/minibuf.c b/src/minibuf.c
index ba8729bdff2..8f1987298b3 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -143,6 +143,14 @@ choose_minibuf_frame_1 (Lisp_Object ignore)
   return Qnil;
 }
 
+DEFUN ("active-minibuffer-window", Factive_minibuffer_window,
+       Sactive_minibuffer_window, 0, 0, 0,
+       doc: /* Return the currently active minibuffer window, or nil if none.  */)
+     (void)
+{
+  return minibuf_level ? minibuf_window : Qnil;
+}
+
 DEFUN ("set-minibuffer-window", Fset_minibuffer_window,
        Sset_minibuffer_window, 1, 1, 0,
        doc: /* Specify which minibuffer window to use for the minibuffer.
@@ -2181,6 +2189,7 @@ properties.  */);
                doc: /* Minibuffer keymap used for reading Lisp expressions.  */);
   Vread_expression_map = Qnil;
 
+  defsubr (&Sactive_minibuffer_window);
   defsubr (&Sset_minibuffer_window);
   defsubr (&Sread_from_minibuffer);
   defsubr (&Seval_minibuffer);
diff --git a/src/window.c b/src/window.c
index bc9f31e03e8..4e8b98a3237 100644
--- a/src/window.c
+++ b/src/window.c
@@ -94,76 +94,376 @@ static Lisp_Object select_window (Lisp_Object, Lisp_Object, int);
 
    This value is always the same as
    FRAME_SELECTED_WINDOW (selected_frame).  */
-
 Lisp_Object selected_window;
 
 /* A list of all windows for use by next_window and Fwindow_list.
    Functions creating or deleting windows should invalidate this cache
    by setting it to nil.  */
-
 Lisp_Object Vwindow_list;
 
 /* The mini-buffer window of the selected frame.
    Note that you cannot test for mini-bufferness of an arbitrary window
    by comparing against this; but you can test for mini-bufferness of
    the selected window.  */
-
 Lisp_Object minibuf_window;
 
 /* Non-nil means it is the window whose mode line should be
    shown as the selected window when the minibuffer is selected.  */
-
 Lisp_Object minibuf_selected_window;
 
 /* Hook run at end of temp_output_buffer_show.  */
-
 static Lisp_Object Qtemp_buffer_show_hook;
 
 /* Incremented for each window created.  */
-
 static int sequence_number;
 
 /* Nonzero after init_window_once has finished.  */
-
 static int window_initialized;
 
 /* Hook to run when window config changes.  */
-
 static Lisp_Object Qwindow_configuration_change_hook;
-/* Incremented by 1 whenever a window is deleted.  */
 
+/* Incremented by 1 whenever a window is deleted.  */
 static int window_deletion_count;
 
 /* Used by the function window_scroll_pixel_based */
-
 static int window_scroll_pixel_based_preserve_x;
 static int window_scroll_pixel_based_preserve_y;
 
 /* Same for window_scroll_line_based.  */
-
 static int window_scroll_preserve_hpos;
 static int window_scroll_preserve_vpos;
+
+static struct window *
+decode_window (register Lisp_Object window)
+{
+  if (NILP (window))
+    return XWINDOW (selected_window);
 
-#if 0 /* This isn't used anywhere.  */
-/* Nonzero means we can split a frame even if it is "unsplittable".  */
-static int inhibit_frame_unsplittable;
-#endif
+  CHECK_LIVE_WINDOW (window);
+  return XWINDOW (window);
+}
+
+static struct window *
+decode_any_window (register Lisp_Object window)
+{
+  if (NILP (window))
+    return XWINDOW (selected_window);
+
+  CHECK_WINDOW (window);
+  return XWINDOW (window);
+}
 
-
 DEFUN ("windowp", Fwindowp, Swindowp, 1, 1, 0,
-       doc: /* Return t if OBJECT is a window.  */)
+       doc: /* Return t if OBJECT is a window and nil otherwise.  */)
   (Lisp_Object object)
 {
   return WINDOWP (object) ? Qt : Qnil;
 }
 
 DEFUN ("window-live-p", Fwindow_live_p, Swindow_live_p, 1, 1, 0,
-       doc: /* Return t if OBJECT is a window which is currently visible.  */)
+       doc: /* Return t if OBJECT is a live window and nil otherwise.
+A live window is a window that displays a buffer.  */)
   (Lisp_Object object)
 {
   return WINDOW_LIVE_P (object) ? Qt : Qnil;
 }
+
+/* Frames and windows.  */
+DEFUN ("window-frame", Fwindow_frame, Swindow_frame, 1, 1, 0,
+       doc: /* Return the frame that window WINDOW is on.
+WINDOW can be any window and defaults to the selected one.  */)
+  (Lisp_Object window)
+{
+  return decode_any_window (window)->frame;
+}
+
+DEFUN ("frame-root-window", Fframe_root_window, Sframe_root_window, 0, 1, 0,
+       doc: /* Return the root window of FRAME_OR_WINDOW.
+If omitted, FRAME_OR_WINDOW defaults to the currently selected frame.
+Else if FRAME_OR_WINDOW denotes any window, return the root window of
+that window's frame.  If FRAME_OR_WINDOW denotes a live frame, return
+the root window of that frame.  */)
+  (Lisp_Object frame_or_window)
+{
+  Lisp_Object window;
+
+  if (NILP (frame_or_window))
+    window = SELECTED_FRAME ()->root_window;
+  else if (WINDOWP (frame_or_window))
+    window = XFRAME (WINDOW_FRAME (XWINDOW (frame_or_window)))->root_window;
+  else
+    {
+      CHECK_LIVE_FRAME (frame_or_window);
+      window = XFRAME (frame_or_window)->root_window;
+    }
+
+  return window;
+}
+
+DEFUN ("minibuffer-window", Fminibuffer_window, Sminibuffer_window, 0, 1, 0,
+       doc: /* Return the window used now for minibuffers.
+If the optional argument FRAME is specified, return the minibuffer window
+used by that frame.  */)
+  (Lisp_Object frame)
+{
+  if (NILP (frame))
+    frame = selected_frame;
+  CHECK_LIVE_FRAME (frame);
+  return FRAME_MINIBUF_WINDOW (XFRAME (frame));
+}
+
+DEFUN ("window-minibuffer-p", Fwindow_minibuffer_p,
+       Swindow_minibuffer_p, 0, 1, 0,
+       doc: /* Return non-nil if WINDOW is a minibuffer window.
+WINDOW can be any window and defaults to the selected one.  */)
+  (Lisp_Object window)
+{
+  return MINI_WINDOW_P (decode_any_window (window)) ? Qt : Qnil;
+}
+
+/* Don't move this to window.el - this must be a safe routine.  */
+DEFUN ("frame-first-window", Fframe_first_window, Sframe_first_window, 0, 1, 0,
+       doc: /* Return the topmost, leftmost live window on FRAME_OR_WINDOW.
+If omitted, FRAME_OR_WINDOW defaults to the currently selected frame.
+Else if FRAME_OR_WINDOW denotes any window, return the first window of
+that window's frame.  If FRAME_OR_WINDOW denotes a live frame, return
+the first window of that frame.  */)
+  (Lisp_Object frame_or_window)
+{
+  Lisp_Object window;
+
+  if (NILP (frame_or_window))
+    window = SELECTED_FRAME ()->root_window;
+  else if (WINDOWP (frame_or_window))
+    window = XFRAME (WINDOW_FRAME (XWINDOW (frame_or_window)))->root_window;
+  else
+    {
+      CHECK_LIVE_FRAME (frame_or_window);
+      window = XFRAME (frame_or_window)->root_window;
+    }
+
+  while (NILP (XWINDOW (window)->buffer))
+    {
+      if (! NILP (XWINDOW (window)->hchild))
+        window = XWINDOW (window)->hchild;
+      else if (! NILP (XWINDOW (window)->vchild))
+        window = XWINDOW (window)->vchild;
+      else
+        abort ();
+    }
+
+  return window;
+}
+
+DEFUN ("frame-selected-window", Fframe_selected_window,
+       Sframe_selected_window, 0, 1, 0,
+       doc: /* Return the selected window of FRAME_OR_WINDOW.
+If omitted, FRAME_OR_WINDOW defaults to the currently selected frame.
+Else if FRAME_OR_WINDOW denotes any window, return the selected window
+of that window's frame.  If FRAME_OR_WINDOW denotes a live frame, return
+the selected window of that frame.  */)
+  (Lisp_Object frame_or_window)
+{
+  Lisp_Object window;
+
+  if (NILP (frame_or_window))
+    window = SELECTED_FRAME ()->selected_window;
+  else if (WINDOWP (frame_or_window))
+    window = XFRAME (WINDOW_FRAME (XWINDOW (frame_or_window)))->selected_window;
+  else
+    {
+      CHECK_LIVE_FRAME (frame_or_window);
+      window = XFRAME (frame_or_window)->selected_window;
+    }
+
+  return window;
+}
+
+DEFUN ("set-frame-selected-window", Fset_frame_selected_window,
+       Sset_frame_selected_window, 2, 3, 0,
+       doc: /* Set selected window of FRAME to WINDOW.
+FRAME must be a live frame and defaults to the selected one.  If FRAME
+is the selected frame, this makes WINDOW the selected window.  Optional
+argument NORECORD non-nil means to neither change the order of recently
+selected windows nor the buffer list.  WINDOW must denote a live window.
+Return WINDOW.  */)
+  (Lisp_Object frame, Lisp_Object window, Lisp_Object norecord)
+{
+  if (NILP (frame))
+    frame = selected_frame;
+
+  CHECK_LIVE_FRAME (frame);
+  CHECK_LIVE_WINDOW (window);
+
+  if (! EQ (frame, WINDOW_FRAME (XWINDOW (window))))
+    error ("In `set-frame-selected-window', WINDOW is not on FRAME");
+
+  if (EQ (frame, selected_frame))
+    return Fselect_window (window, norecord);
+  else
+    return XFRAME (frame)->selected_window = window;
+}
+
+DEFUN ("selected-window", Fselected_window, Sselected_window, 0, 0, 0,
+       doc: /* Return the selected window.
+The selected window is the window in which the standard cursor for
+selected windows appears and to which many commands apply.  */)
+  (void)
+{
+  return selected_window;
+}
+
+/* If select_window is called with inhibit_point_swap non-zero it will
+   not store point of the old selected window's buffer back into that
+   window's pointm slot.  This is needed by Fset_window_configuration to
+   avoid that the display routine is called with selected_window set to
+   Qnil causing a subsequent crash.  */
+static Lisp_Object
+select_window (Lisp_Object window, Lisp_Object norecord, int inhibit_point_swap)
+{
+  register struct window *w;
+  register struct window *ow;
+  struct frame *sf;
+
+  CHECK_LIVE_WINDOW (window);
+
+  w = XWINDOW (window);
+  w->frozen_window_start_p = 0;
+
+  if (NILP (norecord))
+    {
+      ++window_select_count;
+      XSETFASTINT (w->use_time, window_select_count);
+      record_buffer (w->buffer);
+    }
+
+  if (EQ (window, selected_window) && !inhibit_point_swap)
+    return window;
+
+  sf = SELECTED_FRAME ();
+  if (XFRAME (WINDOW_FRAME (w)) != sf)
+    {
+      XFRAME (WINDOW_FRAME (w))->selected_window = window;
+      /* Use this rather than Fhandle_switch_frame
+         so that FRAME_FOCUS_FRAME is moved appropriately as we
+         move around in the state where a minibuffer in a separate
+         frame is active.  */
+      Fselect_frame (WINDOW_FRAME (w), norecord);
+      /* Fselect_frame called us back so we've done all the work already.  */
+      eassert (EQ (window, selected_window));
+      return window;
+    }
+  else
+    sf->selected_window = window;
+
+  /* Store the current buffer's actual point into the
+     old selected window.  It belongs to that window,
+     and when the window is not selected, must be in the window.  */
+  if (!inhibit_point_swap)
+    {
+      ow = XWINDOW (selected_window);
+      if (! NILP (ow->buffer))
+        set_marker_both (ow->pointm, ow->buffer,
+                         BUF_PT (XBUFFER (ow->buffer)),
+                         BUF_PT_BYTE (XBUFFER (ow->buffer)));
+    }
+
+  selected_window = window;
+
+  Fset_buffer (w->buffer);
+
+  BVAR (XBUFFER (w->buffer), last_selected_window) = window;
+
+  /* Go to the point recorded in the window.
+     This is important when the buffer is in more
+     than one window.  It also matters when
+     redisplay_window has altered point after scrolling,
+     because it makes the change only in the window.  */
+  {
+    register EMACS_INT new_point = marker_position (w->pointm);
+    if (new_point < BEGV)
+      SET_PT (BEGV);
+    else if (new_point > ZV)
+      SET_PT (ZV);
+    else
+      SET_PT (new_point);
+  }
+
+  windows_or_buffers_changed++;
+  return window;
+}
+
+DEFUN ("select-window", Fselect_window, Sselect_window, 1, 2, 0,
+       doc: /* Select WINDOW.  Most editing will apply to WINDOW's buffer.
+Also make WINDOW's buffer current and make WINDOW the frame's selected
+window.  Return WINDOW.
+
+Optional second arg NORECORD non-nil means do not put this buffer at the
+front of the buffer list and do not make this window the most recently
+selected one.
+
+Note that the main editor command loop sets the current buffer to the
+buffer of the selected window before each command.  */)
+  (register Lisp_Object window, Lisp_Object norecord)
+{
+  return select_window (window, norecord, 0);
+}
+
+DEFUN ("window-buffer", Fwindow_buffer, Swindow_buffer, 0, 1, 0,
+       doc: /* Return the buffer that WINDOW is displaying.
+WINDOW can be any window and defaults to the selected one.
+If WINDOW is an internal window return nil.  */)
+  (Lisp_Object window)
+{
+  return decode_any_window (window)->buffer;
+}
+
+DEFUN ("window-parent", Fwindow_parent, Swindow_parent, 0, 1, 0,
+       doc: /* Return WINDOW's parent window.
+WINDOW can be any window and defaults to the selected one.
+Return nil if WINDOW has no parent.  */)
+  (Lisp_Object window)
+{
+  return decode_any_window (window)->parent;
+}
+
+DEFUN ("window-vchild", Fwindow_vchild, Swindow_vchild, 0, 1, 0,
+       doc: /* Return WINDOW's first vertical child window.
+WINDOW can be any window and defaults to the selected one.
+Return nil if WINDOW has no vertical child.  */)
+  (Lisp_Object window)
+{
+  return decode_any_window (window)->vchild;
+}
+
+DEFUN ("window-hchild", Fwindow_hchild, Swindow_hchild, 0, 1, 0,
+       doc: /* Return WINDOW's first horizontal child window.
+WINDOW can be any window and defaults to the selected one.
+Return nil if WINDOW has no horizontal child.  */)
+  (Lisp_Object window)
+{
+  return decode_any_window (window)->hchild;
+}
+
+DEFUN ("window-next", Fwindow_next, Swindow_next, 0, 1, 0,
+       doc: /* Return WINDOW's right sibling window.
+WINDOW can be any window and defaults to the selected one.
+Return nil if WINDOW has no right sibling.  */)
+  (Lisp_Object window)
+{
+  return decode_any_window (window)->next;
+}
 
+DEFUN ("window-prev", Fwindow_prev, Swindow_prev, 0, 1, 0,
+       doc: /* Return WINDOW's left sibling window.
+WINDOW can be any window and defaults to the selected one.
+Return nil if WINDOW has no left sibling.  */)
+  (Lisp_Object window)
+{
+  return decode_any_window (window)->prev;
+}
+
 Lisp_Object
 make_window (void)
 {
@@ -217,36 +517,6 @@ make_window (void)
   return val;
 }
 
-DEFUN ("selected-window", Fselected_window, Sselected_window, 0, 0, 0,
-       doc: /* Return the window that the cursor now appears in and commands apply to.  */)
-  (void)
-{
-  return selected_window;
-}
-
-DEFUN ("minibuffer-window", Fminibuffer_window, Sminibuffer_window, 0, 1, 0,
-       doc: /* Return the window used now for minibuffers.
-If the optional argument FRAME is specified, return the minibuffer window
-used by that frame.  */)
-  (Lisp_Object frame)
-{
-  if (NILP (frame))
-    frame = selected_frame;
-  CHECK_LIVE_FRAME (frame);
-  return FRAME_MINIBUF_WINDOW (XFRAME (frame));
-}
-
-DEFUN ("window-minibuffer-p", Fwindow_minibuffer_p,
-       Swindow_minibuffer_p, 0, 1, 0,
-       doc: /* Return non-nil if WINDOW is a minibuffer window.
-WINDOW defaults to the selected window.  */)
-  (Lisp_Object window)
-{
-  struct window *w = decode_window (window);
-  return MINI_WINDOW_P (w) ? Qt : Qnil;
-}
-
-
 DEFUN ("pos-visible-in-window-p", Fpos_visible_in_window_p,
        Spos_visible_in_window_p, 0, 3, 0,
        doc: /* Return non-nil if position POS is currently on the frame in WINDOW.
@@ -424,34 +694,6 @@ Return nil if window display is not up-to-date.  In that case, use
 
 
 
-static struct window *
-decode_window (register Lisp_Object window)
-{
-  if (NILP (window))
-    return XWINDOW (selected_window);
-
-  CHECK_LIVE_WINDOW (window);
-  return XWINDOW (window);
-}
-
-static struct window *
-decode_any_window (register Lisp_Object window)
-{
-  if (NILP (window))
-    return XWINDOW (selected_window);
-
-  CHECK_WINDOW (window);
-  return XWINDOW (window);
-}
-
-DEFUN ("window-buffer", Fwindow_buffer, Swindow_buffer, 0, 1, 0,
-       doc: /* Return the buffer that WINDOW is displaying.
-WINDOW defaults to the selected window.  */)
-  (Lisp_Object window)
-{
-  return decode_window (window)->buffer;
-}
-
 DEFUN ("window-height", Fwindow_height, Swindow_height, 0, 1, 0,
        doc: /* Return the number of lines in WINDOW.
 WINDOW defaults to the selected window.
@@ -3496,106 +3738,6 @@ This function runs `window-scroll-functions' before running
   return Qnil;
 }
 
-/* If select_window is called with inhibit_point_swap non-zero it will
-   not store point of the old selected window's buffer back into that
-   window's pointm slot.  This is needed by Fset_window_configuration to
-   avoid that the display routine is called with selected_window set to
-   Qnil causing a subsequent crash.  */
-
-static Lisp_Object
-select_window (Lisp_Object window, Lisp_Object norecord, int inhibit_point_swap)
-{
-  register struct window *w;
-  register struct window *ow;
-  struct frame *sf;
-
-  CHECK_LIVE_WINDOW (window);
-
-  w = XWINDOW (window);
-  w->frozen_window_start_p = 0;
-
-  if (NILP (norecord))
-    {
-      ++window_select_count;
-      XSETFASTINT (w->use_time, window_select_count);
-      record_buffer (w->buffer);
-    }
-
-  if (EQ (window, selected_window) && !inhibit_point_swap)
-    return window;
-
-  sf = SELECTED_FRAME ();
-  if (XFRAME (WINDOW_FRAME (w)) != sf)
-    {
-      XFRAME (WINDOW_FRAME (w))->selected_window = window;
-      /* Use this rather than Fhandle_switch_frame
-         so that FRAME_FOCUS_FRAME is moved appropriately as we
-         move around in the state where a minibuffer in a separate
-         frame is active.  */
-      Fselect_frame (WINDOW_FRAME (w), norecord);
-      /* Fselect_frame called us back so we've done all the work already.  */
-      eassert (EQ (window, selected_window));
-      return window;
-    }
-  else
-    sf->selected_window = window;
-
-  /* Store the current buffer's actual point into the
-     old selected window.  It belongs to that window,
-     and when the window is not selected, must be in the window.  */
-  if (!inhibit_point_swap)
-    {
-      ow = XWINDOW (selected_window);
-      if (! NILP (ow->buffer))
-        set_marker_both (ow->pointm, ow->buffer,
-                         BUF_PT (XBUFFER (ow->buffer)),
-                         BUF_PT_BYTE (XBUFFER (ow->buffer)));
-    }
-
-  selected_window = window;
-
-  Fset_buffer (w->buffer);
-
-  BVAR (XBUFFER (w->buffer), last_selected_window) = window;
-
-  /* Go to the point recorded in the window.
-     This is important when the buffer is in more
-     than one window.  It also matters when
-     redisplay_window has altered point after scrolling,
-     because it makes the change only in the window.  */
-  {
-    register EMACS_INT new_point = marker_position (w->pointm);
-    if (new_point < BEGV)
-      SET_PT (BEGV);
-    else if (new_point > ZV)
-      SET_PT (ZV);
-    else
-      SET_PT (new_point);
-  }
-
-  windows_or_buffers_changed++;
-  return window;
-}
-
-
-/* Note that selected_window can be nil when this is called from
-   Fset_window_configuration.  */
-
-DEFUN ("select-window", Fselect_window, Sselect_window, 1, 2, 0,
-       doc: /* Select WINDOW.  Most editing will apply to WINDOW's buffer.
-If WINDOW is not already selected, make WINDOW's buffer current
-and make WINDOW the frame's selected window.  Return WINDOW.
-Optional second arg NORECORD non-nil means do not put this buffer
-at the front of the list of recently selected ones and do not
-make this window the most recently selected one.
-
-Note that the main editor command loop selects the buffer of the
-selected window before each command.  */)
-     (register Lisp_Object window, Lisp_Object norecord)
-{
-  return select_window (window, norecord, 0);
-}
-
 static Lisp_Object
 select_window_norecord (Lisp_Object window)
 {
@@ -7125,9 +7267,19 @@ frame to be redrawn only if it is a tty frame.  */);
   defsubr (&Swindow_minibuffer_p);
   defsubr (&Swindowp);
   defsubr (&Swindow_live_p);
+  defsubr (&Swindow_frame);
+  defsubr (&Sframe_root_window);
+  defsubr (&Sframe_first_window);
+  defsubr (&Sframe_selected_window);
+  defsubr (&Sset_frame_selected_window);
   defsubr (&Spos_visible_in_window_p);
   defsubr (&Swindow_line_height);
   defsubr (&Swindow_buffer);
+  defsubr (&Swindow_parent);
+  defsubr (&Swindow_vchild);
+  defsubr (&Swindow_hchild);
+  defsubr (&Swindow_next);
+  defsubr (&Swindow_prev);
   defsubr (&Swindow_height);
   defsubr (&Swindow_width);
   defsubr (&Swindow_full_width_p);
diff --git a/src/window.h b/src/window.h
index b1f6560445e..96e30d98d24 100644
--- a/src/window.h
+++ b/src/window.h
@@ -844,11 +844,15 @@ struct glyph *get_phys_cursor_glyph (struct window *w);
 extern Lisp_Object Qwindowp, Qwindow_live_p;
 extern Lisp_Object Vwindow_list;
 
-EXFUN (Fselected_window, 0);
-EXFUN (Fwindow_minibuffer_p, 1);
-EXFUN (Fdelete_window, 1);
 EXFUN (Fwindow_buffer, 1);
+EXFUN (Fwindow_frame, 1);
 EXFUN (Fget_buffer_window, 2);
+EXFUN (Fwindow_minibuffer_p, 1);
+EXFUN (Fselected_window, 0);
+EXFUN (Fframe_root_window, 1);
+EXFUN (Fframe_first_window, 1);
+EXFUN (Fset_frame_selected_window, 3);
+EXFUN (Fdelete_window, 1);
 EXFUN (Fset_window_configuration, 1);
 EXFUN (Fcurrent_window_configuration, 1);
 extern int compare_window_configurations (Lisp_Object, Lisp_Object, int);