with-temp-buffer: should we set buffer-undo-list to t?

with-temp-buffer: should we set buffer-undo-list to t?

[raman]

Would setting buffer-undo-list to t in the macro  definition of
with-temp-buffer help save some work?

At present we dont do this, and as a consequence, operations within
body of with-tem-buffer may well push entries on the undo stack that
just get thrown away.
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Re: with-temp-buffer: should we set buffer-undo-list to t?

[Noam Postavsky]

On Sat, Mar 11, 2017 at 6:52 PM,  <raman@google.com> wrote:
> Would setting buffer-undo-list to t in the macro  definition of
> with-temp-buffer help save some work?
>
> At present we dont do this, and as a consequence, operations within
> body of with-tem-buffer may well push entries on the undo stack that
> just get thrown away.

Seems it already happens:

(with-temp-buffer
  buffer-undo-list) ;=> t

get-buffer-create has this code:

  bset_undo_list (b, SREF (name, 0) != ' ' ? Qnil : Qt);

So buffers starting with a space have the undo list set to t.

Re: with-temp-buffer: should we set buffer-undo-list to t?

[raman]

Thanks for spotting that -- I had only looked at the defmacro for
with-temp-buffer and missed the connection between temp buffers having a
space in front and the related code in get-buffer-create.
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