xdg-open from within an xdg-app?

[Stephan Bergmann]

[Hi all; I thought I had subscribed to this list long ago, but 
apparently hadn't, and only seen the few mails that got crossposted to 
gnome-os-list; so if the below has already been discussed, please just 
point me to the archives.]

I'm trying to package LibreOffice (LO) as an xdg-app, and one thing LO 
wants to occasionally do is call other apps to handle some URLs (like 
calling a browser when clicking on a hyperlink in a Writer doc), in the 
xdg-open style.  However, doing so from an xdg-app sandbox (even a fully 
privileged one) of course does not work.

So what I thought about is a trivial DBus service running outside the 
sandbox that just forwards any arguments to xdg-open.  Is that something 
that we would want to add?

(In its simplest form, that service would arguably have security 
implications for unprivileged apps, but it could be opt-in on 
--socket=session-bus.  My first aim at least for a sandboxed LO is to 
give it full privileges, anyway.)

Stephan