[PATCH V2] commitextras: make sure keys contains ascii letters, numbers, '_' and '-' only

[Yuya Nishihara]

On Sun, 30 Jul 2017 00:03:49 +0530, Pulkit Goyal wrote:
> # HG changeset patch
> # User Pulkit Goyal <7895pulkit at gmail.com>
> # Date 1501207975 -19800
> #      Fri Jul 28 07:42:55 2017 +0530
> # Branch stable
> # Node ID f0fb7e786aceea12cb422b100c5ccf047b61d45d
> # Parent  850d2ec2cf6a266987a401752c909f95dd8c4c53
> commitextras: make sure keys contains ascii letters, numbers, '_' and '-' only

Queued, thanks.

Can you add a check for an empty key as a follow up?