Re: Git checkout multiple options issue
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jan 28, 2019, 17:29 UTC
- Message-ID
- <xmqqtvhsbsia.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <20190128165515.GA25995@alpha>
Kevin Daudt <me@ikke.info> writes:
Show 16 quoted lines
> On Mon, Jan 28, 2019 at 10:20:02AM -0500, Randall S. Becker wrote: >> On January 28, 2019 9:25, COLLOMB Joris wrote: >> ... >> > git checkout -f -b "branch_name" >> > gives me " Fatal: A branch named 'branch_name' already exists." >> >> Once the branch is created, you can't force its creation, because it is >> already created. Just >> >> git checkout "branch_name" >> >> is sufficient at this point. git is correct to complain that you are trying >> to create a branch that already exists. > > git checkout -B exists, which does exactly that: force create a branch > at a new positon if it already exists.
Correct.
"git checkout -b/-B" is for lazy people to perform two things, i.e. "creating a branch" and "checking the branch out", at the same time.
If we did not allow "git checkout -b newbranch othercommit" and only allowed "git checkout -b newbranch", i.e. to start a branch at the current HEAD, then we could make "git checkout -f -b newbranch" to mean "git checkout -B newbranch", because creating a branch at HEAD and checking it out will not have a risk of overwriting local changes, i.e. no need to force the "checking the branch out" part, so the "--force" option can only mean "force creating the branch".
But because the new branch can begin at the commit whose tree differs at a path that has local modifications, there needs a way to tell the command which part, either "creating a branch" or "checking the branch out", is being forced. Hence, "-f" tells the "checking out the branch" part to do the forcing (e.g. allowing local changes to be overwritten), and "creating a branch" part is told to force with the distinction between "-b" and "-B".