Re: turning off (or enhancing) a couple of new features

[Joe Corneli]

   Joe Corneli wrote:

      Also, the NEWS file documents changes to the `undo' mechanism,

        ** When the undo information of the current command gets really large
        (beyond the value of `undo-outer-limit'), Emacs discards it and warns
        you about it.

      In fact, Emacs doesn't just warn me, I think it actually prompts me
      and asks if I think it is OK to discard the information.  I always
      say yes, and I would like to know how to get it to always just
      *silently* throw the undo information away.  According to the
      documentation I read, it is basically essential that the info be
      jettisoned whenever we get beyond `undo-outer-limit', so I don't
      see why I should be asked/told about it.

   The prompting is controlled by the variable `undo-ask-before-discard'.
   This variable is currently set to t for debugging purposes, but it is
   scheduled to be turned off before release, because a t value can leak
   memory and cause other problems.

OK, thanks, now I know.

   The NEWS documents the planned post-release behavior.

(I don't see this variable mentioned in "~/emacs/etc/NEWS" for

 GNU Emacs 22.0.50.4 (powerpc-apple-darwin7.5.0, X toolkit, Xaw3d
 scroll bars) of 2005-03-24 on hope-of-a-stone.local

so I'm not sure what you mean.)

   Is there a good known reason why you often build up such huge (3 Meg)
   single undo entries?  If you do not offhand know the reason for it,
   like visiting huge files, it could be due to a bug.

It seems to mostly have to do with shell buffers, commands that
generate lots of output, and yes, editing/manipulating large (I
wouldn't say huge) text files.