Re: Dangers of working on a tracking branch

From: Jeff King <peff@peff.net>
Date: Feb 15, 2007, 21:43 UTC
Message-ID: <20070215214352.GA2980@coredump.intra.peff.net>
In-Reply-To: <17876.53654.426022.454712@lisa.zopyra.com>

On Thu, Feb 15, 2007 at 03:21:38PM -0600, Bill Lear wrote:

Show 5 quoted lines

> Ok, so I break the model, what is the harm in that?  Can I no longer
> pull from or push to the remote branch?  Do I corrupt something
> locally?  Does something else break?  I'm trying to formulate an
> explanation to our users why the 1.5 way is superior and I can't just
> say "if you do that you break the model".

The commits you make will not actually go onto that tracking branch; they will be part of a "detached HEAD" (that is, your HEAD doesn't point to _any_ branch). Once you check out a different branch, you will potentially lose those commits (actually, they will still be available through your reflog, but you will have to know to look for them there).

> BTW, my ignorant assumption is that for merging to take place, git
> requires two branches, so 'git pull' will fetch into the tracking
> branch and then merge onto your ... uh ... whatever the name of the
> working version of your tracking branch is.

That's more or less correct. You don't really have to have two branches; doing a 'git pull /path/to/repo branch' will fetch the branch into the temporary FETCH_HEAD name, and merge from that. But yes, the way a raw 'git pull' will work is to first fetch all tracking branches into refs/remotes/origin/*, and then merge from whichever is defined by your config.

And they're usually called "local branches" if you differentiating them from remote tracking branches, or just "branches" otherwise.

> BTW, again, why does git clone not have an option to just create all
> of the "working versions" (better name needed) of tracking branches?

I don't recall anybody asking for it, yet. I think the idea is that those branches would just be clutter. If you want to work on something, it's easy enough to just start a local version of the branch:

  git checkout -b topic origin/topic

-Peff