bug#16493: 24.3.50; (setq search-invisible t) is useless, let's allow to turn visible-mode temporarily on

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Noam Postavsky <npostavs@gmail.com>,  bzg@gnu.org,  16493@debbugs.gnu.org
> Date: Sat, 11 May 2019 16:06:12 -0400
> 
> >> Starting from t, (add-to-invisibility-spec 'foo) also has the weird
> >> result that it *reduces* the number of properties which cause
> >> invisibility (from infinity to 2).
> > Yes, but I don't see that as a problem.
> 
> Here's another way to look at it:
> 
> Give me a circumstance where an Elisp package can make use of the fact
> that buffer-invisibility-spec defaults to t?

That's the wrong way of looking at the issue, if you want to talk
about the aspects that I called "confusing".  I see no technical
problems with using (t) instead of t, I just said that it confuses the
heck out of me, because its semantics is not clear by just looking at
the value.