From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 01 Sep 2016 21:08:08 GMT
Subject: Should "git symbolic-ref -d HEAD" be forbidden?
Message-ID: <xmqqpoonuy4n.fsf@gitster.mtv.corp.google.com>

I think we should.

t1401 expects to be able to, but if you really do it:

	$ cd /tmp
	$ git init throwaway
        $ cd throwaway
        $ git symbolic-ref -d HEAD

the setup machinery considers that you are no longer in a working
tree that is controlled by a repository at .git/ because .git/ is
no longer a valid repository, so you cannot even do

	$ git symbolic-ref HEAD refs/heads/master

to recover.