Re: [PATCH v2 5/6] Add new @ shortcut for HEAD

Duy Nguyen [off-list ref] writes:

On Wed, May 1, 2013 at 4:49 AM, Felipe Contreras
[off-list ref] wrote:

quoted

So HEAD@{0}~0^0 is too much to type, but we can remove '^0', and we can
remove '~0', and we can remove 'HEAD', which leaves us with @{0}, but we
can't remove '{0}'?

This patch allows '@' to be the same as 'HEAD'.

So now we can use 'git show @~1', and all that goody goodness.

Until now '@' was a valid name, but it conflicts with this idea, so lets
make it invalid. Very few people if any probably used this name, if they
did, they can rename it by using the full-path (e.g. refs/heads/@).

People can write master short for refs/heads/master, but can't with
refs/heads/@.

Is it a new problem?

You can not say HEAD to refer to refs/heads/HEAD, either.  To avoid
confusion, we teach "git branch HEAD $commit" to error out (but it
seems that "git checkout -b HEAD $commit" does not).

We probably would want to do the same for '@' when we refactor to
have a central place that knows what the "make sense as refnames at
the syntactic level, but are forbidden for operational purposes"
branch names are. And use it to update "git checkout -b".