bug#1092: compilation-goto-error goes to wrong location when buffer has hidden regions

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> I'd agree that either selective-display should be marked as deprecated,
> or the problem should be fixed. I don't know what the status of
> selective-display is, though - it might be worth bringing this up in
> emacs-devel.

There are several problems with selective-display:
- first and foremost, the variable provides 2 different features:
  - when set to t, it makes CR behave specially (it's a special
    line-separator that makes the next line invisible).
  - when set to a number, it makes all lines indented deeper than this
    number invisible.
- The first use should be declared obsolete because overlays provide
  a much better way to do the same thing.  There might still be a few
  packages out there using this old selective-display thingy but they
  really need to move on.
- The second use should be replaced by a minor mode which provides the
  same feature using overlays, but nobody bothered to do so.
  Maybe because this second use is very rarely useful at all.
  So maybe this second use should be just dropped (i.e. made obsolete
  without providing an alternative).


-- Stefan