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

[Ian Dunn <dunni@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>
> 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?
>

Move point to the start of logical line 19, then move point one visual
line up.  Set that character to be invisible, then move point back to
the start of logical line 19.  Re-position the window twice, then move
point up one visible line.

M-g M-g 19
C-p
C-M-: (add-text-properties (point) (1+ (point)) '(invisible t))
C-n
C-l C-l
C-p

> 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?
>

I try not to assume that everyone has the same key-bindings as me, so I
thought it might help to use the actual command names.  As far as I can
tell, it makes no difference.

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 Finally, your build is slightly outdated, so perhaps see if the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

I updated my build to the most recent version of the emacs-25 branch,
but the problem still persists.  I forgot to mention in my original
report that this seems similar to bug #17047
(https://lists.gnu.org/archive/html/bug-gnu-emacs/2014-03/msg00804.html).
It looks like the old bug addressed the problem with forward-char and
backward-char.  I've checked with next-line, but I've never seen it
happen before.  I only ever see this problem with previous-line.

Thanks for your quick response.