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

[Eli Zaretskii]

> Date: Sat, 12 Jan 2013 17:37:57 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: monnier@iro.umontreal.ca, 13399@debbugs.gnu.org
> 
>  > fit-window-to-buffer should probably call pos-visible-in-window-p with
>  > argument PARTIALLY non-nil, and then it should be possible to get rid
>  > of the loop.
> 
> But PARTIALLY nil means to return nil if the position is only partially
> visible.  And in this case `fit-window-to-buffer' should try to enlarge
> the window.

Should it?  It enlarges the window in line units, so the enlarged
window will again show a partially visible line, no?

> I now call `count-screen-lines' with COUNT-FINAL-NEWLINE t and
> this seems to work although I'm quite sure that it didn't work earlier.

count-screen-lines relies on vertical-motion, which got several
improvements lately.  Maybe this is the reason.