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

[Stefan Monnier]

> Okay. So, I'll recap, and then explain the logic that I am trying to
> implement.

So, IIUC this undo-buffer-undoably-changed is meant to distinguish "new
change since boundary" from "new change since last timer run").

OK, so we were indeed miscommunicating.

But I get the impression that you didn't pay attention to another part
of the logic that we need: the part that pushes a boundary at the end of
a command.  Currently this is done in the C code and is applied only to
the current buffer, but we should change this so it is applied to all
buffers that were modified during the last command.

> - every ten seconds check the size of the undo list, and iff it is
>   bigger than undo-limit, and has less than 2 boundaries, add one at the
>   start.

Why not just unconditionally add a boundary (i.e. regardless of the undo
list size)?  That would make it more useful (because more predictable
and avoid too large undo steps), and would remove the need for
undo-buffer-undoably-changed.


        Stefan