Re: undoing changes automatically

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> > I guess the message means that cancel-change-group couldn't find the
>> > path (through undo entries) going from the current state to the
>> > original state.  More specifically, it means that the current undo-log
>> > does not contains as one of its nthcdr the head of the original
>> > undo logs.  That might be the case if the changes to undo are too
>> > numerous and the undo-log has been truncated to the point where the
>> > undo-info needed to revert the change are not present any more.
>> 
>> I thought of something like this, though I couldn't phrase it as
>> nicely and accurately as you did it  :-)

> If all this is true, and it is necessary to keep the error message
> of cancel-chance-group in the code, then I'd be glad if this error
> message could be replaced by something that is more transparent for
> the average emacs user. I do not know what I could do with it except
> for bringing it up here.

If you can think of a better message, I'm all ears.

The "cancel-change-group: Wrong type argument: listp, t" error should be
fixed OTOH.  And it might indicate that the problem lies elsewhere:
maybe the undo was disabled somewhere within the atomic-change-group.


        Stefan