bug#21207: 25.0.50; Cursor position behaves unpredictably on the 'display text property

[Artur Malabarba]

> Yes, sorry.  The important part is that it's not at the end of the
> string.
>
> In any case, due to the way cursor positioning in these cases is
> implemented, in order to decide that the cursor could be placed on a
> line that is part of the display string, the display engine needs to
> see at least one glyph from that display string on that line.  And a
> newline leaves no glyph.  So if you change your second scenario to
> this:
>
>   (add-text-properties (point) (1+ (point)) '(display "-\n------"))
>
> you will see that the cursor is placed on that line, before the
> newline.

Yes, I see what you mean.