bug#17244: 24.3.90; `line-move-visual' errors when moving across wrapped lines with an overlay property of 'display

[Ivan Andrus]

On Apr 12, 2014, at 5:31 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> Thanks for the report.  I fixed this in revision 116947 on the
> emacs-24 branch.

Thanks for fixing this Eli.

> <rant>
> To tell the truth, Lisp code which covers large portions of buffer
> text with much shorter display strings that include newlines deserves
> to be broken.  The current Emacs display engine was never designed to
> handle situations where the displayed text is so starkly different
> from buffer text, so the result of trying to fix "bugs" such as this
> one is a never-ending series of band-aids, one upon the other, which
> make the code utterly incomprehensible and unmaintainable.
> 
> So I'm this close to refusing to fix such "bugs", and instead asking
> the authors of such Lisp to either find more benign ways of expressing
> what they need, or work around the limitations of the display engine
> in their own Lisp.
> </rant>       

So is the problem having newlines in the 'display property, or hiding large 
portions of the buffer?  Because, in my original use case (my modified version 
of http://www.emacswiki.org/emacs/fold.el) I don’t think I have newlines in the 
display property, though I definitely hide large portions of the buffer.  The 
overlays are also nested, so it might it be related to that?

That said, your change seems to have fixed it.  

Thanks again,
Ivan