Re: enabling evaporation of overlays

[Katsumi Yamaoka <yamaoka@xxxxxxx>]

>>>>> In [emacs-w3m : No.06606]
>>>>>	Masatake YAMATO <jet@gyve.org> wrote:

rms> I think the right fix is in fix_start_end_in_overlays.  When an
rms> insertion occurs next to an overlay whose beginning-marker is the
rms> advancing kind and whose end-marker is not, the overlay should stay
rms> empty.

> I've done this. I hope no backwards overlay in GNU Emacs.
> I will inspect overlay usage in widgets next.

Thanks.  I'm looking forward to the code which will appear in
the CVS head.

> BTW, I found a programming tip in button.el of GNU Emacs.

>     ;; Default properties for buttons
>     (put 'default-button 'face 'button)
[...]
> 	  (overlay-put overlay 'category 'default-button)
> 	  ...)

> With category property, you can give your own default property of
> overlays made in your lisp code. This will be useful in your code.

I didn't know that feature.  It seems very useful.  I've
confirmed it can be used for all the Emacs 21.* series even if
there is no button.el.

;; Isn't it mysterious that button.el has not been contained in
;; the released Emacsen yet?
-- 
Katsumi Yamaoka <yamaoka@jpl.org>