bug#18764: 24.4; electric-indent in *scratch* signals an error

[Eli Zaretskii]

> Cc: 18764@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Mon, 18 Jun 2018 12:33:34 +0300
> 
> On 6/17/18 6:48 AM, Eli Zaretskii wrote:
> 
> > I submit that any errors in code that tries to indent should be
> > suppressed, as they are not relevant to what the user wanted.  If
> > those errors are important in other contexts, they will pop up there,
> > and can then decide what to do with them.
> 
> That's going to make user complaints like "why it doesn't indent" or "it 
> doesn't indent right" harder to debug and address.

IMO, this is a lesser evil.  And if it turns out to be a real problem,
we could always add a variable to control whether such errors are
silently ignored.