[PATCH 5 of 9] revset: abort the query when there is no revision for "rev()" (BC)

[Matt Mackall]

On Mon, 2015-03-30 at 14:19 -0400, Augie Fackler wrote:
> On Tue, Mar 31, 2015 at 01:31:52AM +0900, FUJIWARA Katsunori wrote:
> > At Mon, 30 Mar 2015 14:05:45 +0900,
> > Yuya Nishihara wrote:
> > >
> > > On Mon, 30 Mar 2015 03:34:27 +0900, FUJIWARA Katsunori wrote:
> > > > # HG changeset patch
> > > > # User FUJIWARA Katsunori <foozy at lares.dti.ne.jp>
> > > > # Date 1427653752 -32400
> > > > #      Mon Mar 30 03:29:12 2015 +0900
> > > > # Node ID f9e9783d4f10af2974d77dbfaacd217f24fd3035
> > > > # Parent  efa05b47238ba2a0bca69cd40b8e2e1aed3a2cf2
> > > > revset: abort the query when there is no revision for "rev()" (BC)
> > > >
> > > > Before this patch, "REV" and "rev(REV)" differ from each other:
> > > >
> > > >     target      REV          rev(REV)
> > > >     ----------- ------------ ------------
> > > >     known       pass         pass
> > > >     hidden      abort (*1)   pass (=> empty set)
> > > >     unknown     abort        pass (=> empty set)
> > > >
> > > >     (*1) abort with "use --hidden" hint
> > > >
> > > > For equivalence between them, "rev(REV)" should abort the query for
> > > > hidden or unknown revisions, even though this may break backward
> > > > compatibility for existing tools, which expect that "rev()" doesn't
> > > > abort the query in any cases.
> > >
> > > I thought about it before, but because rev() didn't raise error for 3 years,
> > > I'm afraid that there would be some tools that rely on the existing behavior.
> >
> > What about introducing new predicates "revnum()" (and "hashid()") or
> > so for strict behavior ? (should we make "rev()"/"id()" deprecate, too ?)
> 
> I'd be in favor of something like that iff we can't declare the
> no-args behavior of rev() and id() to be bugs, which would be my
> strong preference. cc'ing mpm so he can weigh in.

"no-args behavior"?

We seem to be preparing to change the behavior with explicitly naming
hidden changesets, but no one wants to tell me about it.

-- 
Mathematics is the supreme nostalgia of our time.