Re: [Emacs-diffs] master fd8f724: * src/xdisp.c (overlay_arrows_changed_p): Fix last change.

[Stefan Monnier]

>> > The 3 variables related to overlay-arrow whose changes need to trigger
>> > redisplay of the respective buffers: overlay-arrow-position,
>> > overlay-arrow-string, and overlay-arrow-bitmap.
>> But that means we need to watch variable assignments, marker
>> modifications, and symbol property modifications.  Using overlays gets
>> us all this "for free" because we already watch all overlay modifications.
> Variables and markers, yes.  Symbol properties: I don't see why would
> we need to watch them.

overlay-arrow-string and overlay-arrow-bitmap are a symbol properties.
(overlay-arrow-string is *also* a variable, but overlay-arrow-bitmap isn't).

> Anyway, it was just a thought.  It sounds like a conceptually simpler,
> even if the implementation is somewhat hairy.

To me the conceptually simpler option is to use overlays (at least, when
I first learned about overlay-arrows many years ago it took me a while
to understand them because I expected them to be represented by special
kinds of overlays).


        Stefan