bug#23053: 25.0.92; error in cc-mode when editing C# file with a generic class inheritance

[Alan Mackenzie <acm@muc.de>]

Hello, Jostein.

On Sat, Mar 26, 2016 at 08:26:00AM +0100, Jostein Kjønigsen wrote:

> On Fri, Mar 25, 2016, at 07:54 PM, Alan Mackenzie wrote:
> > Thanks.  That was useful, and enabled me to reproduce the problem.  It's
> > a separate bug from the one Saulius reported with csharp-mode, and occurs
> > only in the Emacs master branch.  To be precise, a new variable
> > introduced in that branch hadn't been given a proper initial value for
> > Java (or, indeed, C#), so had the default value nil, which led to the
> > error happening.

> > This bug has now been fixed and committed to the master branch of the
> > Emacs git repository.  Would you please get the latest version, and
> > confirm that the bug has been satisfactorally fixed.  Thanks!


> I've tested for both java-mode and csharp-mode.

> Once recompiled/reinstalled from melpa/marmalade csharp-mode loads fine
> now. Thanks for the fix!

Thanks, that's great!

[ .... ]

> I'll consider this issue fixed at this point, and look into this single
> test [ related to fontification ] later.

OK.

> >> Byte-compiling csharp-mode triggers a warning which so far haven't been
> >> an issue for csharp-mode:

> > Yes.  Somebody in the Emacs team has decided that the second argument,
> > previously optional, is now mandatory.  I wish people wouldn't do things
> > like that.  The only thing sensible here is to add a second argument,
> > nil, to each call to looking-back.

> I've stalled doing this, due to not knowing if I will be changing the
> semantics of the code. Do you know if inserting this nil-parameter is
> what implicitly done by the compiler in cases such as these? Is such a
> change guaranteed "safe"?

> If you can confirm that, I can update the code to get rid of simple
> issues like this.

Adding the nil argument for the new version of `looking-back' is exactly
equivalent to leaving it out on the earlier version.  Earlier versions
of `looking-back' will continue to work unchanged after adding that
explicit nil.  That argument actually holds a limit position for backward
searching.  If it is convenient to calculate a sensible limit, this might
speed up C# Mode when using `looking-back', since with nil it may be
looking arbitrarily far back.

> > Can I ask you, as maintainer of csharp-mode:
> > (i) To insert "(eval-when-compile (require 'cc-langs))" near the top of
> >   csharp-mode.el.
> > (ii) To add something to the manual telling users to compile
> >   csharp-mode.el with the Emacs it's going to be run with.

> > (i) should help ensure csharp-mode gets properly compiled.  (ii) should
> > also help ensure csharp-mode is properly compiled.  :-)

> Consider (i) done. As for (ii) that's usually not done by the user
> itself, but by Emacs whenever there's an update to the package on MELPA
> or marmalade.

OK.

> I can add a note to the related bug on the csharp-mode issue-tracker
> that this issue is resolved by reinstalling/recompiling the package
> though.

That would be good.

> Cheers!

I think it's time to close this bug, which I will do.  Thanks for all the
help!

> -- 
> Jostein Kjønigsen
> jostein@kjonigsen.net / jostein@secure.kjonigsen.net

-- 
Alan Mackenzie (Nuremberg, Germany).