[PATCH 2 of 2] templatekw: add a {negrev} keyword

[Yuya Nishihara]

On Fri, 19 Jan 2018 14:32:34 -0500, Augie Fackler wrote:
> On Wed, Jan 17, 2018 at 10:14:30PM -0500, Jordi Gutiérrez Hermoso wrote:
> > # HG changeset patch
> > # User Jordi Gutiérrez Hermoso <jordigh at octave.org>
> > # Date 1516243120 18000
> > #      Wed Jan 17 21:38:40 2018 -0500
> > # Node ID cbf1d676a938e78d40cd3504dd916f787bcb47ee
> > # Parent  701f8a9defdc09bb63f2596e2fc426f2e78da313
> > templatekw: add a {negrev} keyword
> 
> This is a really interesting idea. It mostly has driven me crazy that
> negative revnums work, but this sort of provides a reason for their
> existence I guess.
> 
> That said, I'm too wary of locking this in on the last day before a
> freeze, so let's plan to discuss this after the freeze sometime in
> early February? Maybe set a calendar reminder to rebase && resend this
> patch then.

Can you rename the keyword to something saying that isn't actually a "rev"?
Negative integers aren't always usable where revision number is expected,
e.g. rev(n), and -1 means either null or tip depending on context.