[PATCH 2 of 2 v2] extensions: catch uisetup and extsetup failures and don't let them break hg

[Yuya Nishihara]

On Thu, 8 Jun 2017 12:57:30 -0400, Augie Fackler wrote:
> 
> > On Jun 8, 2017, at 12:00, Yuya Nishihara <yuya at tcha.org> wrote:
> > 
> >>     # Call aftercallbacks that were never met.
> >>     for shortname in _aftercallbacks:
> >> -        if shortname in _extensions:
> >> +        if shortname in _extensions or shortname in broken:
> >>             continue
> > 
> > Perhaps _aftercallbacks had to check if _extensions[shortname] is None or not.
> > That's an old bug.
> 
> Oh, yeah, it should. I fixed it in this patch, but can split it if v3 looks right.

Oops, my bad. _aftercallbacks here should never be called once extension is
successfully imported. So loaded is always False.