bug#11133: 24.0.94; Cursor gets "stuck" on an indented line with wrapped overlay

[Ivan Andrus]

On Mar 30, 2012, at 6:12 PM, Eli Zaretskii wrote:
>> From: Ivan Andrus <darthandrus@gmail.com>
>> Date: Fri, 30 Mar 2012 16:47:05 +0200
>> 
>> Put the following (including comments) in a buffer and evaluate.
>> 
>> #+begin_src emacs-lisp
>> ;; Note that the next line is indented
>> ;; This buffer is for notes you don't want to save, and for Lisp 
>> evaluation.;; If you want to create a file, visit that file with C-x C-f,;; 
>> then enter the text in that file's own buffer.
>> 
>> ;; evaluate this
>> (let ((ov (make-overlay
>>         (progn (goto-char (point-min))
>>                (forward-line)
>>                (back-to-indentation)
>>                (point))
>>         (progn (end-of-line)
>>                (point))
>>         nil t nil)))
>> (overlay-put ov 'display
>>             (make-string 500 ?b)))
>> 
>> #+end_src
>> 
>> Now run `previous-line' several times and it will get stuck at the
>> indentation of the bbbbb line.  If you have an extremely wide screen you
>> may need to shrink the emacs window so that the bbbb line wraps.  Also
>> note that running `previous-line' with a large prefix-argument will
>> move past the line
> 
> More accurately, "large enough" is the number of screen lines taken by
> the overlay string.  In my case, it was 7.
> 
>> This does not seem to be a problem in Emacs 22.1.1 in a terminal which
>> is the only other emacs I have easy access to.
> 
> This is a bug in visual line movement.  Visual line movement was
> introduced in Emacs 23, that's why you don't see this in Emacs 22.  In
> Emacs 23, the cursor gets stuck similarly, so this is not a regression
> wrt Emacs 23.  Disable line-move-visual with the current 24 trunk, and
> the problem will go away in Emacs 24 as well.
> 
> I will take a look when I have time.

That makes sense.

Thanks,
Ivan