(Fdisplay_buffer): Move call to

Vsplit_window_preferred_function out of conditions that check
if window is eligible for vertical splitting.
When Vsplit_window_preferred_function is non-nil, call it and use
its non-nil return value as window.  Otherwise, continue doing
vertical splitting using Fsplit_window with arg horflag=nil.
(syms_of_window) <Vsplit_window_preferred_function>: Change the
default value from `split-window' to nil.

diff --git a/src/ChangeLog b/src/ChangeLog
index 844f42e7301db20e6fdf7034f4a748f8cb6aa998..9061ffc23592b1f3603690b84a87c148affe7adc 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,14 @@
+2008-03-29  Juri Linkov  <juri@jurta.org>
+
+       * window.c (Fdisplay_buffer): Move call to
+       Vsplit_window_preferred_function out of conditions that check
+       if window is eligible for vertical splitting.
+       When Vsplit_window_preferred_function is non-nil, call it and use
+       its non-nil return value as window.  Otherwise, continue doing
+       vertical splitting using Fsplit_window with arg horflag=nil.
+       (syms_of_window) <Vsplit_window_preferred_function>: Change the
+       default value from `split-window' to nil.
+
 2008-03-29  Juri Linkov  <juri@jurta.org>
 
        * callint.c (Fcall_interactively): Revert 2008-03-16 change

diff --git a/src/window.c b/src/window.c
index 8cf2a45e6f2fe189bf3e65964fe22d56cf76e488..3b93a6fdc9f41c6ed79244c1a18596c8edc27f1c 100644 (file)
--- a/src/window.c
+++ b/src/window.c
@@ -3848,16 +3848,22 @@ displayed.  */)
       else
        window = Fget_largest_window (frames, Qt);
 
-      /* If the largest window is tall enough, full-width, and either eligible
-        for splitting or the only window, split it.  */
-      if (!NILP (window)
-         && ! FRAME_NO_SPLIT_P (XFRAME (XWINDOW (window)->frame))
-         && WINDOW_FULL_WIDTH_P (XWINDOW (window))
-              && (window_height (window) >= split_height_threshold
-                  || (NILP (XWINDOW (window)->parent)))
-         && (window_height (window)
-             >= (2 * window_min_size_2 (XWINDOW (window), 0))))
-       window = call1 (Vsplit_window_preferred_function, window);
+      if (!NILP (Vsplit_window_preferred_function))
+       tem = call1 (Vsplit_window_preferred_function, window);
+
+      if (!NILP (tem))
+       window = tem;
+      else
+       /* If the largest window is tall enough, full-width, and either eligible
+          for splitting or the only window, split it.  */
+       if (!NILP (window)
+           && ! FRAME_NO_SPLIT_P (XFRAME (XWINDOW (window)->frame))
+           && WINDOW_FULL_WIDTH_P (XWINDOW (window))
+           && (window_height (window) >= split_height_threshold
+               || (NILP (XWINDOW (window)->parent)))
+           && (window_height (window)
+               >= (2 * window_min_size_2 (XWINDOW (window), 0))))
+         window = Fsplit_window (window, Qnil, Qnil);
       else
        {
          Lisp_Object upper, other;
@@ -3867,12 +3873,12 @@ displayed.  */)
             splitting and selected or the only window, split it.  */
          if (!NILP (window)
              && ! FRAME_NO_SPLIT_P (XFRAME (XWINDOW (window)->frame))
-                  && ((EQ (window, selected_window)
-                       && window_height (window) >= split_height_threshold)
-                      || (NILP (XWINDOW (window)->parent)))
-                  && (window_height (window)
-                      >= (2 * window_min_size_2 (XWINDOW (window), 0))))
-           window = call1 (Vsplit_window_preferred_function, window);
+             && ((EQ (window, selected_window)
+                  && window_height (window) >= split_height_threshold)
+                 || (NILP (XWINDOW (window)->parent)))
+             && (window_height (window)
+                 >= (2 * window_min_size_2 (XWINDOW (window), 0))))
+           window = Fsplit_window (window, Qnil, Qnil);
          else
            window = Fget_lru_window (frames, Qnil);
          /* If Fget_lru_window returned nil, try other approaches.  */
@@ -7596,9 +7602,12 @@ If there is only one window, it is split regardless of this value.  */);
               doc: /* Function to use to split a window.
 This is used by `display-buffer' to allow the user to choose whether
 to split windows horizontally or vertically or some mix of the two.
+When this variable is nil, `display-buffer' splits windows vertically.
+Otherwise, `display-buffer' calls this function to split a window.
 It is called with a window as single argument and should split it in two
-and return the new window.  */);
-  Vsplit_window_preferred_function = intern ("split-window");
+and return the new window, or return an appropriate existing window
+if splitting is not eligible.  */);
+  Vsplit_window_preferred_function = Qnil;
 
   DEFVAR_INT ("window-min-height", &window_min_height,
              doc: /* *Delete any window less than this tall (including its mode line).