py3: return False early while checking whether None is a key in lazymanifest...
py3: return False early while checking whether None is a key in lazymanifest
In this patch we returns False early if we are trying to check whether None is a
key in lazymanifest. The reason I added a diff is that on Python 3, it goes into
the lazy manifest code an returns a TypeError. I checked with Durham that
whether None can be a possible key in lazymanifest and he said "no". So it's
safe to have this if statement.
This fixes `hg merge` on Python 3.
Differential Revision:
https://phab.mercurial-scm.org/D852
