bug#20241: 25.0.50; `setq' with only one argument

[Alan Mackenzie <acm@muc.de>]

Hello, John.

On Wed, Nov 25, 2015 at 12:37:20PM -0800, John Wiegley wrote:
> >>>>> Artur Malabarba <bruce.connor.am@gmail.com> writes:

> > On 25 Nov 2015 7:40 pm, "John Wiegley" <jwiegley@gmail.com> wrote:
> >> Ok, let's go with this then:

> >> Evaluation: Run-time error
> >> Compilation: Compile-time warning
> >> Execution: Run-time error (same as Evaluation)

> >> I think that's the convergence point for the three of us, amirite?

I've committed a fix for the above.  The compiler outputs the same
message it previously did.  The generated code DOESN'T do the first n
assignements when there are 2n+1 arguments; it just signals an error
like Fsetq does.

> > Yes, that's the final behaviour we should have. 
> > (Though, like I said, I'd prefer it if the errors were postponed to the next
> > release. And Alan was having second thoughts about being so quick with the
> > errors too (IIUC, he's investigating Gelpa code now).) 

> I'd accept a deprecation warning that notifies it will become an error in
> 25.2, then.

I've committed the entire change.  If there's going to be pain, let's
just get it over with immediately.

> John

-- 
Alan Mackenzie (Nuremberg, Germany).