* lisp.h (XCONS, XSTRING, XSYMBOL, XFLOAT, XPROCESS, XWINDOW, XSUBR, XBUFFER):

Verify correct object type before returning pointer, using eassert.
* frame.h (XFRAME): Likewise.

* buffer.c (Frename_buffer, Fset_buffer_multibyte,
swap_out_buffer_local_variables, Fmove_overlay): Don't apply XSYMBOL, XBUFFER,
etc, to values that may be nil or of the wrong type.
* data.c (set_internal): Likewise.
* dispextern.h (WINDOW_WANTS_MODELINE_P, WINDOW_WANTS_HEADER_LINE_P): Likewise.
* fileio.c (auto_save_1): Likewise.
* insdel.c (check_markers): Likewise.
* marker.c (buf_charpos_to_bytepos, unchain_marker): Likewise.
* undo.c (record_insert): Likewise.
* vmsproc.c (child_sig): Likewise.
* window.c (unshow_buffer, window_loop): Likewise.
* xterm.c (x_erase_phys_cursor): Likewise.

1 files changed, 6 insertions, 3 deletions

diff --git a/src/window.c b/src/window.c
index 95edbf8e13e..72547cad4b1 100644
--- a/src/window.c
+++ b/src/window.c
@@ -905,7 +905,8 @@ unshow_buffer (w)
      So don't clobber point in that buffer.  */
   if (! EQ (buf, XWINDOW (selected_window)->buffer)
       /* This line helps to fix Horsley's testbug.el bug.  */
-      && !(w != XWINDOW (b->last_selected_window)
+      && !(WINDOWP (b->last_selected_window)
+           && w != XWINDOW (b->last_selected_window)
            && EQ (buf, XWINDOW (b->last_selected_window)->buffer)))
     temp_set_point_both (b,
                          clip_to_bounds (BUF_BEGV (b),
@@ -915,7 +916,8 @@ unshow_buffer (w)
                                          marker_byte_position (w->pointm),
                                          BUF_ZV_BYTE (b)));
   
-  if (w == XWINDOW (b->last_selected_window))
+  if (WINDOWP (b->last_selected_window)
+      && w == XWINDOW (b->last_selected_window))
     b->last_selected_window = Qnil;
 }
 
@@ -1633,7 +1635,8 @@ window_loop (type, obj, mini, frames)
           case GET_LARGEST_WINDOW:
             /* Ignore dedicated windows and minibuffers.  */
             if (MINI_WINDOW_P (XWINDOW (w))
-                || !NILP (XWINDOW (w)->dedicated))
+                || !NILP (XWINDOW (w)->dedicated)
+                || NILP (best_window))
               break;
             {
               struct window *best_window_ptr = XWINDOW (best_window);