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

[Chong Yidong <cyd@stupidchicken.com>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> 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.

I don't see how this could possibly work.  We can't update
buffer-really-modified-tick in Lisp code for arbitrary buffer changes
(that's the whole point of Martin's patch --- you have to do it at the
C level).  And you can't use it to manage a general-purpose variable
like imenu-menubar-modified-tick, because that keeps track of the
value of (buffer-modified-tick) as of the last call to
`imenu-update-menubar', so imenu must reset
imenu-menubar-modified-tick during each call to
`imenu-update-menubar'.