1 files changed, 19 insertions, 3 deletions

diff --git a/src/window.c b/src/window.c
index 2e2f6427b5f..e2659885f19 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1969,7 +1969,7 @@ window_loop (type, obj, mini, frames)
   GCPRO1 (windows);
   best_window = Qnil;
 
-  for (; CONSP (windows); windows = CDR (windows))
+  for (; CONSP (windows); windows = XCDR (windows))
     {
       struct window *w;
 
@@ -3667,7 +3667,7 @@ temp_output_buffer_show (buf)
 #endif
   set_buffer_internal (old);
 
-  if (!EQ (Vtemp_buffer_show_function, Qnil))
+  if (!NILP (Vtemp_buffer_show_function))
     call1 (Vtemp_buffer_show_function, buf);
   else
     {
@@ -5831,7 +5831,23 @@ the return value is nil.  Otherwise the value is t.  */)
   else
     {
       if (XBUFFER (new_current_buffer) == current_buffer)
-        old_point = PT;
+        /* The code further down "preserves point" by saving here PT in
+           old_point and then setting it later back into PT.  When the
+           current-selected-window and the final-selected-window both show
+           the current buffer, this suffers from the problem that the
+           current PT is the window-point of the current-selected-window,
+           while the final PT is the point of the final-selected-window, so
+           this copy from one PT to the other would end up moving the
+           window-point of the final-selected-window to the window-point of
+           the current-selected-window.  So we have to be careful which
+           point of the current-buffer we copy into old_point.  */
+        if (EQ (XWINDOW (data->current_window)->buffer, new_current_buffer)
+            && WINDOWP (selected_window)
+            && EQ (XWINDOW (selected_window)->buffer, new_current_buffer)
+            && !EQ (selected_window, data->current_window))
+          old_point = XMARKER (XWINDOW (data->current_window)->pointm)->charpos;
+        else
+          old_point = PT;
       else
         /* BUF_PT (XBUFFER (new_current_buffer)) gives us the position of
            point in new_current_buffer as of the last time this buffer was