Re: undo weirdness with insert-file-contents

[martin rudalics]

> The value of buffer-undo-list is:
>
> (nil
>  (10 . 21)
>  (1 . 21)
>  (t 0 . 0))

The (1 . 21) entry is silly and obviously breaks undoing the prior
(insert "Foo: bar\n").  Although EQ (XCAR (tem), lbeg) was not very
intelligent, setting this to (XCAR (tem) == lbeg) doesn't seem to help
either.  Please try again with the attached patch.

GDB doesn't work here currently, so I can't debug this.  But could you
try finding out in `insert-file-contents' (1) why the test in

              if (CONSP (tem) && INTEGERP (XCAR (tem)) &&
                  INTEGERP (XCDR (tem)) && (XCAR (tem) == lbeg))
                /* In the non-visiting case record only the final insertion. */
                current_buffer->undo_list =
                  Fcons (Fcons (lbeg, lend), Fcdr (old_undo));

fails and (2) which value old_undo has here?  Thanks in advance.

*** fileio.c.~1.602.~   Thu Feb 14 20:41:44 2008
--- fileio.c    Thu Feb 28 13:59:42 2008
***************
*** 4674,4680 ****
  
        /* Save old undo list and don't record undo for decoding. */
        old_undo = current_buffer->undo_list;
-       current_buffer->undo_list = Qt;
  
        if (NILP (replace))
        {
--- 4674,4679 ----
***************
*** 4768,4774 ****
            {
              Lisp_Object tem = XCAR (old_undo);
              if (CONSP (tem) && INTEGERP (XCAR (tem)) &&
!                 INTEGERP (XCDR (tem)) && EQ (XCAR (tem), lbeg))
                /* In the non-visiting case record only the final insertion. */
                current_buffer->undo_list =
                  Fcons (Fcons (lbeg, lend), Fcdr (old_undo));
--- 4767,4773 ----
            {
              Lisp_Object tem = XCAR (old_undo);
              if (CONSP (tem) && INTEGERP (XCAR (tem)) &&
!                 INTEGERP (XCDR (tem)) && (XCAR (tem) == lbeg))
                /* In the non-visiting case record only the final insertion. */
                current_buffer->undo_list =
                  Fcons (Fcons (lbeg, lend), Fcdr (old_undo));