ref: 91884b5863294fafccdc737182ef5a24fb258e70
parent: f02778f3d7a1d12670995160d16db6cf51ac3db4
author: Ori Bernstein <ori@eigenstate.org>
date: Tue Mar 24 00:32:08 EDT 2020
don't allow merging a branch to itself we used to be able to make merge commits from a branch to itself, or from a branch that was a fast forward of another, but this is a dumb thing to do.