Re: [Emacs-diffs] fix/no-undo-boundary-on-secondary-buffer-change c7a6601 1/5: undo-size can count number of boundaries.

[Stefan Monnier]

>>> +  if(NILP (Vundo_buffer_undoably_changed)){
>>> +    Fset (Qundo_buffer_undoably_changed,Qt);
>>> +    safe_run_hooks (Qundo_first_undoable_change_hook);
>>> +  }
>> Why do you need Vundo_buffer_undoably_changed?
>> Doesn't (car-safe buffer-undo-list) give you the same information?
> No. The point is that this can be reset when ever I choose, and so it
> may well occur *not* after a boundary.

But why would you want to set it not after a boundary?

> hands of the lisp developer, since they can reset
> "buffer-unably-changed" as they want, which will result in a new call
> to the hook.

When is this needed/useful?

> I have chosen not to add a "undoable-change" hook, because I didn't need
> it. The first change hook calls rarely, so the performance issues with
> handling this change in lisp are, I think, unimportant.

Agreed.


        Stefan