bug#25592: Feature request: sorting overlays

[Eli Zaretskii]

> Cc: 25592@debbugs.gnu.org
> From: Clément Pit--Claudel <clement.pitclaudel@live.com>
> Date: Thu, 2 Feb 2017 14:41:21 -0500
> 
> I'm writing a function that copies overlay properties to text properties.

That function probably converts overlays by traversing buffer
positions from beginning to end, no?  Then overlays-at should be what
you need, and next-overlay-change is your friend to move to the next
"interesting" position when you are done with this one.

Isn't that what you are doing?

> I reimplemented compare_overlays in ELisp, but that seems brittle.

How did you implement in Lisp the "last resort" of comparison, which
compares addresses of the C structs?