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

[Eli Zaretskii]

> From: Stefan Monnier <monnier@IRO.UMontreal.CA>
> Cc: David Engster <deng@randomsample.de>, 15045@debbugs.gnu.org,
>         "Eric M. Ludlam" <eric@siege-engine.com>, Eli Zaretskii <eliz@gnu.org>
> Date: Thu, 08 Aug 2013 17:26:50 -0400
> 
> > If arbitrary timers can execute during the lexer's call to
> > accept-process-output or input-pending-p, then doesn't that mean
> > jit-lock-deferred-fontify can run too?
> 
> Yes.

No, I don't think so, because idle timers don't run.

> > If removing timers' sit-for calls is the solution,
> 
> It's a workaround.

I think the right solution is to not call input-pending-p etc. during
lexer run.