* window.c (Vwindow_point_insertion_type): New var.

(set_window_buffer): Use it.
(syms_of_window): Init and export it to Lisp.
* progmodes/compile.el (compilation-mode):
Set window-point-insertion-type.
(compilation-filter): Don't use insert-before-markers any more.
* emacs-lisp/trace.el (trace-make-advice):
Set window-point-insertion-type in the trace buffer.
* startup.el (normal-top-level): Set window-point-insertion-type in
*Messages*.
* net/telnet.el (telnet-mode): Set window-point-insertion-type.
(telnet-filter): Don't use insert-before-markers any more.
* comint.el (comint-mode): Set window-point-insertion-type.
(comint-output-filter): Don't use insert-before-markers any more.
* button.el (make-text-button): Allow `start' to be a string.

1 files changed, 15 insertions, 3 deletions

diff --git a/src/window.c b/src/window.c
index 7af0c6db711..27db0296dcf 100644
--- a/src/window.c
+++ b/src/window.c
@@ -167,6 +167,10 @@ static Lisp_Object Vwindow_configuration_change_hook;
 
 Lisp_Object Vscroll_preserve_screen_position;
 
+/* Non-nil means that text is inserted before window's markers.  */
+
+Lisp_Object Vwindow_point_insertion_type;
+
 /* Incremented by 1 whenever a window is deleted.  */
 
 int window_deletion_count;
@@ -3420,6 +3424,8 @@ set_window_buffer (window, buffer, run_hooks_p, keep_margins_p)
       Fset_buffer (buffer);
     }
 
+  XMARKER (w->pointm)->insertion_type = !NILP (Vwindow_point_insertion_type);
+
   if (!keep_margins_p)
     {
       /* Set left and right marginal area width etc. from buffer.  */
@@ -3486,9 +3492,11 @@ This function runs the hook `window-scroll-functions'.  */)
   else if (! EQ (tem, Qt))      /* w->buffer is t when the window
                                    is first being set up.  */
     {
-      if (!NILP (w->dedicated) && !EQ (tem, buffer))
-        error ("Window is dedicated to `%s'",
-               SDATA (XBUFFER (tem)->name));
+      if (!EQ (tem, buffer))
+        if (EQ (w->dedicated, Qt))
+          error ("Window is dedicated to `%s'", SDATA (XBUFFER (tem)->name));
+        else
+          w->dedicated = Qnil;
 
       unshow_buffer (w);
     }
@@ -7151,6 +7159,10 @@ by full screens.
 Any other value means point always keeps its screen position.  */);
   Vscroll_preserve_screen_position = Qnil;
 
+  DEFVAR_LISP ("window-point-insertion-type", &Vwindow_point_insertion_type,
+               doc: /* Type of marker to use for `window-point'.  */);
+  Vwindow_point_insertion_type = Qnil;
+
   DEFVAR_LISP ("window-configuration-change-hook",
                &Vwindow_configuration_change_hook,
                doc: /* Functions to call when window configuration changes.