Re: jit lock sit-for provokes redisplay provokes imenu

[Richard Stallman]

    1. Should the value returned by `buffer-chars-modified-tick' always
    (invariantly) imply the value returned by `buffer-modified-tick'?

I do not understand "imply" in this context.

                                                                       With
    other words, suppose we have a thing called CHAR_MODIFF: Would we have
    to support the invariant

                      MODIFF >= CHAR_MODIFF >= SAVE_MODIFF

Yes, that is the idea.

                      if (MODIFF - 1 == SAVE_MODIFF)
                        SAVE_MODIFF++;

    I think that's innocuous but, if someone wanted to increment SAVE_MODIFF
    in order to "ignore" a _text-property_ change only, the invariant above
    could get violated.  Is anyone aware of whether such a hack exists or is
    planned somewhere?

They should update CHAR_MODIFF too.

    3. `first-change-hook' currently runs whenever a text-property is
    assigned (by font-lock, for example).  I believe this should change with
    the new function too?

No, I think that should stay the same.  This change is safe because
ALL it will do is create CHAR_MODIFF and provide a function to examine
it.