[PATCH 2 of 3] context: override workingctx.hex() to avoid a crash

[Yuya Nishihara]

On Mon, 15 Jun 2015 13:09:57 -0500, Matt Mackall wrote:
> On Tue, 2015-06-16 at 00:26 +0900, Yuya Nishihara wrote:
> > On Mon, 15 Jun 2015 00:28:58 -0400, Matt Harbison wrote:
> > > # HG changeset patch
> > > # User Matt Harbison <matt_harbison at yahoo.com>
> > > # Date 1434333857 14400
> > > #      Sun Jun 14 22:04:17 2015 -0400
> > > # Node ID f5f5e4ae488d9cae8111e9a212f647ed1430a019
> > > # Parent  9c738d2588313bb624465495a8923b293c45b999
> > > context: override workingctx.hex() to avoid a crash
> > > 
> > > Since node is None for workingctx, it can't use the base class implementation of
> > > 'hex(self.node())'.
> > > 
> > > It doesn't appear that there are any current callers of this, but there will be
> > > when archive supports 'wdir()'.  Since 'hg id' prints "p1.node() + '+'" for a
> > > dirty working copy, this does too.  That of course means that it isn't possible
> > > to call 'bin(ctx.hex())', but that seems circuitous.  Having the '+' seems like
> > > a useful distinction when building the .hg_archival.txt file.
> > > 
> > > diff --git a/mercurial/context.py b/mercurial/context.py
> > > --- a/mercurial/context.py
> > > +++ b/mercurial/context.py
> > > @@ -1334,6 +1334,12 @@
> > >      def __contains__(self, key):
> > >          return self._repo.dirstate[key] not in "?r"
> > >  
> > > +    def hex(self):
> > > +        hex = self.p1().hex()
> > > +        if self.dirty():
> > > +            hex += '+'
> > > +        return hex
> > 
> > I won't argue, but I have to say it won't be so useful.
> 
> I think this is pretty iffy. We might want to instead do something
> analogous to null and assign fff... to the working copy. If I were
> smarter way back when, I might have made the scheme look like:
> 
> rev     hash
> 0       00000  <- null revision
> 1       ???    <- first revision
> ...     
> maxint ffff   <- working copy

I would agree if it were 2008 (though I would insist that rev should be
len(repo) for ease of arithmetic operation.)

IMHO, wctx.hex() should be comparable to hex(wctx.node()), but changing
wctx.node() to '\xff...' would break many things. I doubt if we'll want to
go such route just for wdir().