Comment 100 for bug 18995

(In reply to comment #22)
> (In reply to comment #21)
> > And does Fx will use by default the default application setting up in the
> > desktop user like with xdg-open?
>
> That may be a different bug. This bug is related to ease of use in choosing an
> alternative, non-default application. (In that we offer an alternative to the
> file picker dialog.) If there's a problem on Linux with Fx sending downloaded
> content to default handlers or if that functionality can be improved, we should
> spin off a different bug or (if applicable) re-open one of the dupes.

(Also - this bug relates to choosing the default handler in prefs, as it's called up there too.)