Re: Bug in `next-line' when last char in line has after-string property

[storm@cua.dk (Kim F. Storm)]

Ralf Angeli <angeli@caeruleus.net> writes:

> * Kim F. Storm (2007-01-05) writes:
>
>> Everybody, please watch out for problems with line movement in buffers
>> with overlay and text-property strings.
>
> If you execute the following code which inserts a few strings into the
> buffer *foo* and then puts three overlays in the buffer where each one
> is covering a line break in the buffer and using a line break in the
> display string, the line in the middle will be left out if one tries
> to move point up using `C-p' several times.  Downwards with `C-n' is
> okay.
>
> This is not a regression, but also happened like this before your last
> change.  It just caught my eye when checking for problems with the new
> code.
>
> (progn
>   (pop-to-buffer (get-buffer-create "*foo*"))
>   (dotimes (i 5)
>     (insert (make-string 10 ?x) "\n"))
>   (let ((ov (make-overlay 17 24)))
>     (overlay-put ov 'display "aaa\n"))
>   (let ((ov (make-overlay 29 35)))
>     (overlay-put ov 'display "aaa\n"))
>   (let ((ov (make-overlay 40 46)))
>     (overlay-put ov 'display "aaa\n")))

Indeed.  It is pretty easy to construct expamples like that which
break the current code.  It needs a big overhaul after the release.

But thanks for testing -- and testing that the latest change 
didn't make things worse :-)

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk