Graft should signal a conflict but silently drops one side:

[Matt Mackall]

On Mon, 2014-06-09 at 17:31 +0000, Arnau Castello wrote:
> I have come across a situation where I'm trying to graft  a revision
> which updates one .hgsubstate on top of a another branch, where all
> the substates are different from either the graft or the parent of the
> graft.

Can I get you to turn this into a bug report on our bug tracker?

http://bz.selenic.com/

-- 
Mathematics is the supreme nostalgia of our time.