[PATCH 2 of 8] exthelper: reintroduce the ability to register revsets

[Yuya Nishihara]

On Fri, 28 Dec 2018 01:47:16 -0500, Matt Harbison wrote:
> # HG changeset patch
> # User Matt Harbison <matt_harbison at yahoo.com>
> # Date 1545963977 18000
> #      Thu Dec 27 21:26:17 2018 -0500
> # Node ID fed98646d0421021268ea0b4f91e0d1870bc4bde
> # Parent  7598b362dfbf7cb43a14fdd9296f0d1f4fd67627
> exthelper: reintroduce the ability to register revsets

Queued the series, thanks.

>      def merge(self, other):
>          self._uicallables.extend(other._uicallables)
>          self._uipopulatecallables.extend(other._uipopulatecallables)
>          self._extcallables.extend(other._extcallables)
>          self._repocallables.extend(other._repocallables)
> +        self.revsetpredicate._table.update(other.revsetpredicate._table)

We might need some merge mechanism in registrar itself, so name duplicates
are reported properly.