Re: text properties

[Paul Pogonyshev]

> > Is it expected that evaluating this form sets `modified' flag
> > of the current buffer
> 
> Yes.

OK, since this is not a bug I have to rephrase my question.

How do I quickly remove all text properties from a buffer without
touching the `modified' flag?

I have also noted this strange (from my point of view) behaviour
of overlays:

* `after-string' seems to never get highlighted with the value
  of `face' property.  `before-string' is normally highlighted,
  but when the overlay's text is invisible, it doesn't.

* Consider two overlays set on consequent regions of text, for
  instance an overlay over each of the two `x' letters here:

        xx

  Each of the overlays is set to invisible and has a
  `before-string'.  Only one `before-string' is displayed, even
  though the overlays are still considered different (i.e.
  `overlays-in' lists both of them).

In case you wonder what the hell I'm doing with invisible overlays:
I'm trying to get `—' displayed as `---', but with a non-
default face, so that I can distinguish between a dash and three
hyphens in a row.

Paul