X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/b347b3fd3fbbdd5f009294edd406696889f34329..b3561514f631090ea1af4b6a04aaa8790654595d:/src/undo.c

diff --git a/src/undo.c b/src/undo.c
index 49dc4453d1..ec6f9d6b1d 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -1,5 +1,5 @@
 /* undo handling for GNU Emacs.
-   Copyright (C) 1990, 1993, 1994 Free Software Foundation, Inc.
+   Copyright (C) 1990, 1993, 1994, 2000 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -73,7 +73,7 @@ record_insert (beg, length)
 	  && INTEGERP (XCDR (elt))
 	  && XINT (XCDR (elt)) == beg)
 	{
-	  XSETINT (XCDR (elt), beg + length);
+	  XSETCDR (elt, make_number (beg + length));
 	  return;
 	}
     }
@@ -102,7 +102,8 @@ record_delete (beg, string)
   if (NILP (pending_boundary))
     pending_boundary = Fcons (Qnil, Qnil);
 
-  if (current_buffer != XBUFFER (last_undo_buffer))
+  if (BUFFERP (last_undo_buffer)
+      && current_buffer != XBUFFER (last_undo_buffer))
     Fundo_boundary ();
   XSETBUFFER (last_undo_buffer, current_buffer);
 
@@ -167,7 +168,8 @@ record_marker_adjustment (marker, adjustment)
   if (NILP (pending_boundary))
     pending_boundary = Fcons (Qnil, Qnil);
 
-  if (current_buffer != XBUFFER (last_undo_buffer))
+  if (!BUFFERP (last_undo_buffer) 
+      || current_buffer != XBUFFER (last_undo_buffer))
     Fundo_boundary ();
   XSETBUFFER (last_undo_buffer, current_buffer);
 
@@ -201,7 +203,8 @@ record_first_change ()
   if (EQ (current_buffer->undo_list, Qt))
     return;
 
-  if (current_buffer != XBUFFER (last_undo_buffer))
+  if (!BUFFERP (last_undo_buffer)
+      || current_buffer != XBUFFER (last_undo_buffer))
     Fundo_boundary ();
   XSETBUFFER (last_undo_buffer, current_buffer);
 
@@ -254,10 +257,10 @@ record_property_change (beg, length, prop, value, buffer)
 }
 
 DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0,
-  "Mark a boundary between units of undo.\n\
-An undo command will stop at this point,\n\
-but another undo command will undo to the previous boundary.")
-  ()
+       doc: /* Mark a boundary between units of undo.
+An undo command will stop at this point,
+but another undo command will undo to the previous boundary.  */)
+     ()
 {
   Lisp_Object tem;
   if (EQ (current_buffer->undo_list, Qt))
@@ -270,7 +273,7 @@ but another undo command will undo to the previous boundary.")
 	{
 	  /* If we have preallocated the cons cell to use here,
 	     use that one.  */
-	  XCDR (pending_boundary) = current_buffer->undo_list;
+	  XSETCDR (pending_boundary, current_buffer->undo_list);
 	  current_buffer->undo_list = pending_boundary;
 	  pending_boundary = Qnil;
 	}
@@ -375,7 +378,7 @@ truncate_undo_list (list, minsize, maxsize)
   /* Truncate at the boundary where we decided to truncate.  */
   if (!NILP (last_boundary))
     {
-      XCDR (last_boundary) = Qnil;
+      XSETCDR (last_boundary, Qnil);
       return list;
     }
   else
@@ -383,15 +386,16 @@ truncate_undo_list (list, minsize, maxsize)
 }
 
 DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0,
-  "Undo N records from the front of the list LIST.\n\
-Return what remains of the list.")
-  (n, list)
+       doc: /* Undo N records from the front of the list LIST.
+Return what remains of the list.  */)
+     (n, list)
      Lisp_Object n, list;
 {
   struct gcpro gcpro1, gcpro2;
   Lisp_Object next;
-  int count = specpdl_ptr - specpdl;
+  int count = BINDING_STACK_SIZE ();
   register int arg;
+  
 #if 0  /* This is a good feature, but would make undo-start
 	  unable to do what is expected.  */
   Lisp_Object tem;
@@ -403,21 +407,25 @@ Return what remains of the list.")
     list = Fcdr (list);
 #endif
 
-  CHECK_NUMBER (n, 0);
+  CHECK_NUMBER (n);
   arg = XINT (n);
   next = Qnil;
   GCPRO2 (next, list);
 
-  /* Don't let read-only properties interfere with undo.  */
+  /* In a writable buffer, enable undoing read-only text that is so
+     because of text properties.  */
   if (NILP (current_buffer->read_only))
     specbind (Qinhibit_read_only, Qt);
 
+  /* Don't let `intangible' properties interfere with undo.  */
+  specbind (Qinhibit_point_motion_hooks, Qt);
+
   while (arg > 0)
     {
-      while (1)
+      while (CONSP (list))
 	{
-	  next = Fcar (list);
-	  list = Fcdr (list);
+	  next = XCAR (list);
+	  list = XCDR (list);
 	  /* Exit inner loop at undo boundary.  */
 	  if (NILP (next))
 	    break;
@@ -428,8 +436,8 @@ Return what remains of the list.")
 	    {
 	      Lisp_Object car, cdr;
 
-	      car = Fcar (next);
-	      cdr = Fcdr (next);
+	      car = XCAR (next);
+	      cdr = XCDR (next);
 	      if (EQ (car, Qt))
 		{
 		  /* Element (t high . low) records previous modtime.  */
@@ -471,7 +479,6 @@ Return what remains of the list.")
 	      else if (INTEGERP (car) && INTEGERP (cdr))
 		{
 		  /* Element (BEG . END) means range was inserted.  */
-		  Lisp_Object end;
 
 		  if (XINT (car) < BEGV
 		      || XINT (cdr) > ZV)