bug#22098: 25.0.50; visual-line-mode and invisible text causes cursor to jump

[Eli Zaretskii <eliz@gnu.org>]

> From: dunni@gnu.org
> Date: Sat, 05 Dec 2015 15:47:00 -0500
> 
> emacs -Q output.txt
> M-x visual-line-mode
> ;; Scroll just after the long line of text in the middle of the screen,
> ;; then position the cursor at the first character at that visual line.
> C-M-: (add-text-properties (point) (1+ (point)) '(invisible t))
> next-line
> recenter-top-bottom
> previous-line
> 
> The cursor should jump to the top of the screen.  This isn't always the
> case, as it sometimes moves to the bottom.  It seems to only happen when
> the window needs to be repositioned.

I seem to be unable to reproduce this on my system.  Maybe I didn't
understand the exact place where to put the invisible property.  What
is the value of point there?

Also, is it really necessary to invoke the commands via M-x, or do you
see the same problem when you use C-n, C-l, and C-p instead?

Finally, your build is slightly outdated, so perhaps see if the
problem persists with the current emacs-25 branch.

Thanks.