bug#21368: 25.0.50; Core navigation commands fail in a multi-line intangible text with fringe

[Eli Zaretskii]

> From: Vitalie Spinu <spinuvit@gmail.com>
> Cc: 21368@debbugs.gnu.org
> Date: Sat, 29 Aug 2015 21:17:43 +0200
> 
> Well, I just recalled why I didn't use overlays when I wrote that visual
> breakpoints code about 5 years ago. I wanted the breakpoints to be moved with
> the text on copy/paste. With overlays that's not possible.

You can use overlays only for displaying the breakpoint, and use text
properties to indicate a breakpoint.

Or override the copy/paste commands to reinstate the overlay at the
new place.