git branch --set-upstream regression in master

This used to be possible on the checked out branch:

  $ git branch master --set-upstream origin/master

Now it gives "fatal: Cannot force update the current branch." which is
broken. You should be able to setup/change the tracking information on
the checked out branch.

It's apparently due to ci/forbid-unwanted-current-branch-update.

Sorry I don't have time to contribute a patch at the moment.

(BTW, --set-upstream still needs to be fixed so that these mean the same thing:

  $ git branch master --set-upstream origin/master
  $ git branch --set-upstream origin/master master

and to just allow:

  $ git branch --set-upstream origin/master

w/o having to specify the checked-out branch.)

j.