Branch deletion (Re: [RFC] fast-import: note deletion command)

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Sep 18, 2011, 21:18 UTC
Message-ID: <20110918211836.GI2308@elie>
In-Reply-To: <CAGdFq_hpA95Kj4eMr4e1duuXTpr+OkkwF4K5bTapXEi9UjWcSA@mail.gmail.com>

Sverre Rabbelier wrote:

> Is this perhaps a good moment to also think about branch deletion?
> That came up earlier as well, and thinking about that might give us
> some insights in how to deal with deletions uniformly.

Sorry, my earlier reply missed the point. To answer your question: Dmitry's RFC was about deleting individual notes rather than entire notes refs, so it is not too closely related to branch deletion.

A new "deleteref" command would be a very simple addition, and the UI seems pretty obvious. The main concern in adding such a thing is that it destroys history, while currently "git fast-import" without -f does not provide any commands that can do that. So presumably one would want to do one of the following:

 - only allow deletion of refs that were not present at the start of
   the import, or
 - add a command-line option to permit deletion of refs, so it doesn't
   happen by mistake when misparsing a stream.

It would also be interesting to see an example use (do you remember the earlier thread where it came up?) to make sure the UI fits it well. In most typical cases I can imagine, direct use of "git update-ref -d" would work better. In the case of remote helpers, IIRC there was already a need for the transport-helper to handle the final ref updates so "git fetch" can write a nice notice about them to the console.