Re: [ITCH] Specify refspec without remote

Jeff King wrote:

All refspecs conform to a very simple format:

    quux
    +quux
    quux:baz
    +quux:baz

All of them fail at git_connect(). The third and fourth are equivalent and take a little longer to fail than the first two, because ssh tries to resolve the hostname "quux" or "+quux".

Okay, so I was hoping that we could first attempt to push as usual, and fallback to pushing with the refspec set to argv[0] (if argc is 1); this approach is foolproof and doesn't involve any guessing. Unfortunately, it's going to be very hard, as the callstack to the final git_connect() failure looks like:

    git_connect()
    connect_setup()
    get_refs_via_connect()
    transport_push()
    push_with_options()
    do_push()

Now, it's nearly impossible to propagate the error back from git_connect() to do_push() and switch the refspec. It's not a simple callstack either: there are callbacks being setup and called.

There's one small consolation in all this: all refspecs are match match the !is_url() condition in transport.c:939 get_transport(), and no preceding conditions. This means that there is one place to check if it could possibly be a ref, that's not very deep in the callstack, and return something to the caller appropriately. Currently, get_transport() always returns a valid struct transport with no extra information; maybe we can change this?

Duy's approach of using a special "-" is trivial to implement, but doesn't make me happy. There's no reason I can't have 'git push master +pu foo:bar'.

Thoughts?