[MERGE] special case the no-args version of revision-info

[Michael Hudson]

Robert Collins wrote:
> Robert Collins has voted reject.
> Status is now: Vetoed
> Comment:
> yeah, this is a cute but basically wrong approach, its code that we 
> don't need.

Well fair enough.

> I'd approve a fix to the revision spec to special case -1 though :), as 
> that has the benefit that it is in the correct location for maintainers 
> to see.

That would still leave a call to get_revid_to_revno_map() unless you 
hack somewhere else too, I think?

Anyway, I'm out of time for this until Monday.

Cheers,
mwh