bug#13399: 24.3.50; Word-wrap can't wrap at zero-width space U-200B

[Eli Zaretskii]

> Date: Fri, 11 Jan 2013 19:06:24 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: Eli Zaretskii <eliz@gnu.org>, 13399@debbugs.gnu.org
> 
> How could `posn-at-point' possibly work if the display is not up to
> date?

Very simply: it simulates the display.  See pos_visible_p (which
posn-at-point calls).  That's what I meant when I said that doing this
for determining the line width or height should be easy.