Re: undo weirdness with insert-file-contents

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> I recommend you compile your Emacs with -DUSE_LISP_UNION_TYPE so the
>> compiler will explain to you where you're going wrong: XCAR (tem) is
>> a Lisp_Object, not an integer, so it cannot be compared with ==, but
>> only with EQ (which doesn't strike me as particularly non-intelligent in
>> this instance).

> Indeed.  Miles please try to debug with the attached patch instead.

> *** fileio.c.~1.602.~	Thu Feb 14 20:41:44 2008
> --- fileio.c	Thu Feb 28 20:21:18 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;
  
But this patch is clearly problematic, if one believe the comment: it
would cause the generation of undo info during the decoding step.
I understand that this info will be thrown away later, but we don't want
to pay the corresponding price.


        Stefan