Re: disabling undo boundaries

[phillip.lord@newcastle.ac.uk (Phillip Lord)]

David Kastrup <dak@gnu.org> writes:

> phillip.lord@newcastle.ac.uk (Phillip Lord) writes:
>
>> David Kastrup <dak@gnu.org> writes:
>>>
>>> The problem _I_ see is that it is in general not just "a command" which
>>> may touch another buffer, but also compilation buffers, timer events,
>>> font lock and a number of other background activities not immediately
>>> caused by key presses.
>>
>>
>> I don't think this is an issue, because Emacs is single-threaded. So,
>> all of these events happen *between* commands which, in general, means
>> that an undo-boundary has gone onto the current-buffer anyway.
>
> Not for self-insert-command.  Not for stuff like shell-command-on-region
> that has to wait for material to arrive.

I thought shell-command-on-region still arrives between commands, but I
have not looked at the code. You are more likely to be correct than I.

My feeling is that my patch is likely to remove problems caused by
asynchronicity rather than cause it. The logic is simpler and undo
boundaries are not added based on something that has happened in the
past.

Phil