Re: Fill column indicator functionality

[Ergus]

On Sat, Apr 06, 2019 at 09:49:49AM +0300, Eli Zaretskii wrote:
> > From: Óscar Fuentes <address@hidden>
> > Date: Fri, 05 Apr 2019 23:10:46 +0200
> >
> > I have a patch from some days ago applied here, sorry if this is
> > outdated, but I see something suspicious. After M-x customize-variable
> > display-fill-column-indicator-character :
> >
> >
> > Hide display-fill-column-indicator-character: nil
> >     State : STANDARD. (mismatch)
> >    Character to draw the indicator when ‘display-fill-column-indicator’ is non-n
> >
> >
> > That "nil" and "mismatch" are not right. This is the definition of the
> > variable in xdisp.c:
> >
> >
> >   DEFVAR_LISP ("display-fill-column-indicator-character", 
> > Vdisplay_fill_column_indicator_character,
> >     doc: /* Character to draw the indicator when 
> > `display-fill-column-indicator' is non-nil.
> > The default is U+2502 but a good alternative is (ascii 124) if
> > the font in fill-column-face does not support Unicode characters.  */);
> >   Vdisplay_fill_column_indicator_character = Qnil;
> >   DEFSYM (Qdisplay_fill_column_indicator_character, 
> > "display-fill-column-indicator-character");
> >   Fmake_variable_buffer_local (Qdisplay_fill_column_indicator_character);
>
> Hmm... why do we need those DEFSYMs?  I don't think the Qfoo symbols
> are ever used in C, are they?  Do the problems go away if you remove
> the DEFSYMS?
Hi Eli:

I just followed the same schema than the display-line-numbers variables
some lines before. (and many other variables)

What are actually the Qfoo symbols for? I thought they where for make
buffer local variables?

Actually the question is: Why are we not using those?  instead of
Vdisplay_fill_column_indicator_character?

Maybe these are dumb questions, but now is when the real doubt came out.