bug#28248: 26.0.50; display-line-numbers does not affect window-width / window-text-width

[Eli Zaretskii]

On October 17, 2017 9:19:11 AM GMT+03:00, Steve Purcell <steve@sanityinc.com> 
wrote:
> On 17 Oct 2017, at 15:34, Eli Zaretskii <eliz@gnu.org> wrote:
> > 
> >> That would be the actual amount of "screen estate used up for
> >> line-number display".
> >> 
> >> Can I rely on the extra value always being 2?
> > 
> > As long as we don't change the implementation, yes.  Alternatively,
> > you can call line-number-display-width with the optional argument
> and
> > get the result in pixels, in which case it includes everything (you
> > can divide by frame-char-width to get the result back in columns).
> 
> 
> Thanks, this is helpful. I have some code which calculates the width
> of the buffer contents in characters, and calculating this pixelwise
> works nicely for me.
> 
> The odd thing is that there’s a one character discrepancy between
> graphical and terminal frames. It’s not related to the new line
> numbers support, since an adjustment for that discrepancy has always
> been necessary in the code, and the native line numbers are not
> present in the terminal anyway. Any idea where that one-column
> difference might be coming from?
> 
> https://github.com/purcell/page-break-lines/blob/610dbdc9d39a37912e2b8bfbd3e3d15c7e5d622f/page-break-lines.el#L128-L134

The space reserved for the continuation glyph?  Note that this can also happen
on GUI frames, if the user disables the fringes.

Wouldn't window-text-width suit your needs better?