Re: [rudalics@gmx.at: Re: jit lock sit-for provokes redisplay provokes imenu]

[Richard Stallman <rms@gnu.org>]

    How about this?  It adds jit-lock-pre-stealth-fontify-hook and
    jit-lock-post-stealth-fontify-hook, which are normal hooks run before
    and after each chunk of stealth fontification.  Then imenu can use
    this to avoid menu bar updates resulting from stealth fontification.

It looks good to me.

Stefan wrote:

    This only eliminates one particular source of unwanted updates.  I don't
    think this code is worth the trouble.

That cause of unwanted updates is the only one we know of.  Nothing
else is likely to change the buffer in the background.  It's a fairly
simple and safe solution to the problem that we are working on, and I
think that's definitely worth the trouble.

      At the very least, add it to
    font-lock rather than jit-lock.

Why would that be better?

    Better yet, introduce a macro `with-buffer-unmodified' like the one used in
    jit-lock, and make it manage a `buffer-really-modified-tick', kind of like
    the buffer-chars-modified-tick.  Then use it in jit-lock/font-lock
    and friends.

That seems a lot more trouble, and I don't see that it is needed.