bug#15045: Point jumps inappropriately around time of Semantic lexing

[Stefan Monnier]

>> >> Right, that would do it.
>> >> What happens if you remove the calls to sit-for from time.el?
>> > You cannot ensure redisplay without that.
>> I don't know what scenario you have in mind.
> Any one.  Emacs enters redisplay for any number of reasons, but you
> can never be sure it will do so at any specific point unless you force
> redisplay at that point.  As you well know, in general, while Lisp
> code runs, Emacs does not redisplay.

Of course, but that's true in general.  What makes it more true in
display-time-event-handler?  Remember that display-time-update (called
just before the sit-for) ends with a call to force-mode-line-update.

In practice, is there any important scenario where
display-time-event-handler's sit-for is useful?


        Stefan