*** fileio.c.~1.602.~	Thu Feb 14 20:41:44 2008
--- fileio.c	Sun Mar  2 12:03:00 2008
***************
*** 3730,3735 ****
--- 3730,3736 ----
    int read_quit = 0;
    Lisp_Object old_Vdeactivate_mark = Vdeactivate_mark;
    int we_locked_file = 0;
+   int empty_undo_list = NILP (current_buffer->undo_list);
  
    if (current_buffer->base_buffer && ! NILP (visit))
      error ("Cannot do file visiting in an indirect buffer");
***************
*** 4593,4598 ****
--- 4594,4622 ----
    if (CODING_MAY_REQUIRE_DECODING (&coding)
        && (inserted > 0 || CODING_REQUIRE_FLUSHING (&coding)))
      {
+       if (CONSP (current_buffer->undo_list)
+ 	  && ! NILP (XCAR (current_buffer->undo_list)))
+ 	/* If the undo list is non-empty and undo information is
+ 	   recorded, insert an undo boundary unless we already have one.
+ 	   This is needed to avoid that record_insert combines the
+ 	   present insertion with an earlier one and consequently the
+ 	   mechanism fails that compares the start position of the
+ 	   insertion before vs that after the format-decode step.  */
+ 	Fundo_boundary ();
+       else if (empty_undo_list
+ 	       && MODIFF <= SAVE_MODIFF
+ 	       && NILP (visit) && NILP (replace))
+ 	/* Else if the present insertion is the very first change of the
+ 	   current buffer, undo information is recorded, and we are
+ 	   neither visiting a file nor replacing buffer contents, make
+ 	   sure we record the insertion as a first change in the
+ 	   undo-list.  This is needed in order to avoid that undoing the
+ 	   insertion leaves the buffer's modified state set.  */
+ 	{
+ 	  current_buffer->undo_list = Qnil;
+ 	  record_first_change ();
+ 	}
+ 
        move_gap_both (PT, PT_BYTE);
        GAP_SIZE += inserted;
        ZV_BYTE -= inserted;
***************
*** 4604,4611 ****
        coding_system = CODING_ID_NAME (coding.id);
      }
    else if (inserted > 0)
!     adjust_after_insert (PT, PT_BYTE, PT + inserted, PT_BYTE + inserted,
! 			 inserted);
  
    /* Now INSERTED is measured in characters.  */
  
--- 4628,4651 ----
        coding_system = CODING_ID_NAME (coding.id);
      }
    else if (inserted > 0)
!     {
!       if (CONSP (current_buffer->undo_list)
! 	  && ! NILP (XCAR (current_buffer->undo_list)))
! 	/* Insert an undo boundary unless there's one here.  See
! 	   explanation above.  */
! 	Fundo_boundary ();
!       else if (empty_undo_list
! 	       && MODIFF <= SAVE_MODIFF
! 	       && NILP (visit) && NILP (replace))
! 	/* Make sure the first insertion is counted as a change.  See
! 	   explanation above.  */
! 	{
! 	  current_buffer->undo_list = Qnil;
! 	  record_first_change ();
! 	}
!       adjust_after_insert (PT, PT_BYTE, PT + inserted, PT_BYTE + inserted,
! 			   inserted);
!     }
  
    /* Now INSERTED is measured in characters.  */