bug#9549: 24.0.50; longlines showing hard newlines breaks display

[Eli Zaretskii]

> From: "Miguel V. S. Frasson" <mvsfrasson@gmail.com>
> Date: Mon, 19 Sep 2011 00:02:14 -0300
> 
> 1) emacs -Q
> 
> 2) get some text with some long lines (spaces are necessary).
> 
> I do this copying "test " and yanking several times, making several
> paragraphs (see recent input below).
> 
> 3) M-x longlines-mode
> 
> 4) M-x longlines-show-hard-newlines
> 
> 5) use arrow keys (up and down) to navigate through the text.
> 
> Apparently, when point crosses two C-j, the displayed point goes to
> upper right corner (blinks there as it does normally) giving the
> impression that point is there.  Sometimes it even "recenters" as if
> point where elsewhere.  When (real) point leaves 2 C-j, point behaves
> normally.

Fixed in revision 105856.