bug#27427: 26.0.50; Native line numbers lead to display error in company-mode popup

[Eli Zaretskii]

> Date: Mon, 26 Jun 2017 10:23:44 +0200
> From: martin rudalics <rudalics@gmx.at>
> CC: alexanderm@web.de, 27427@debbugs.gnu.org
> 
>  > Without going into details, how do I figure out the width which line
>  > number glyphs are taking up? Any way to do that without calling
>  > posn-at-point at the beginning-of-visual-line?
> 
> You'd probably need a function ‘window-line-number-width’ callable after
> the current glyph matrix was calculated.

Or maybe a new value of the argument to window-body-width which would
cause it to return the width excluding the line-number part?