(Fdisplay_buffer): If the other window is smaller

than its peer, even out their heights.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/window.c b/src/window.c
index c6c95e68405..96588a8623d 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1946,6 +1946,8 @@ Returns the window displaying BUFFER.")
         window = Fsplit_window (window, Qnil, Qnil);
       else
         {
+          Lisp_Object upper, lower, other;
+
           window = Fget_lru_window (frames);
           /* If the LRU window is selected, and big enough,
              and can be split, split it.  */
@@ -1974,6 +1976,24 @@ Returns the window displaying BUFFER.")
           if (NILP (window))
             window = Fframe_first_window (Fselected_frame ());
 #endif
+          /* If window appears above or below another,
+             even out their heights.  */
+          if (!NILP (XWINDOW (window)->prev))
+            other = upper = XWINDOW (window)->prev, lower = window;
+          if (!NILP (XWINDOW (window)->next))
+            other = lower = XWINDOW (window)->next, upper = window;
+          if (!NILP (other)
+              /* Check that OTHER and WINDOW are vertically arrayed.  */
+              && XWINDOW (other)->top != XWINDOW (window)->top
+              && XWINDOW (other)->height > XWINDOW (window)->height)
+            {
+              int total = XWINDOW (other)->height + XWINDOW (window)->height;
+              struct window *old_selected_window = selected_window;
+
+              selected_window = XWINDOW (upper);
+              change_window_height (total / 2 - XWINDOW (upper)->height, 0);
+              selected_window = old_selected_window;
+            }
         }
     }
   else