Re: [PATCH v3 1/2 / RFC] builtin/branch: stop supporting the use of --set-upstream option

Kaartic Sivaraam [off-list ref] writes:

1. Duplicate the check done in 'builtin/branch.c' in
'builtin/checkout.c'. This doesn't
    sound good to me.

Doesn't sound good to me, either.  Some refactoring to make it
easier to reuse it from the new caller would be necessary.