bug#21468: 24.5; When next-line (visual) crosses overlay with before-string="\n" point goes to column 0

[Noam Postavsky]

On 10/10/15, Eli Zaretskii <eliz@gnu.org> wrote:
>> Date: Fri, 9 Oct 2015 19:34:43 -0400
>> From: Noam Postavsky <npostavs@users.sourceforge.net>
>> - On a truncated line with the overlay, move-end-of-line skips to the
>> next line. (I tried to avoid this by only adding the stretched space
>> when it's going to be visible. But that just made things worse
>> (looping in the display engine))
>>
>> - When at the end of line, next-line goes to the end-of-line instead
>> of staying on the same column.
>
> Are these caused by the 'cursor' property, i.e. do not happen if that
> property is not used?

They're not caused by the 'cursor' property, although it makes the 2nd
case more visually surprising.

>
> In any case, I'd appreciate a short self-contained test case for each
> of these two issues, as I'm not sure I understand what's going on.
>

Using attached 21468-overlay.el

The 1st case:

   emacs -Q -l 21468-overlay.el -f 21468-test-eol-skip

then hit C-e. Point lands at the end of line 19 instead of the end of
line 18 where it started.

The 2nd case

   emacs -Q -l 21468-overlay.el -f 21468-test-eol-col-movement

then hit C-e C-n. Point lands at the end of line 8 instead of line 8,
column 33 which is what happens when there is no overlay.

21468-overlay.el
Description: Binary data