On Sun, Jan 15, 2023 at 7:23 PM Carlo Marcelo Arenas Belón
[off-list ref] wrote:

On Sat, Jan 14, 2023 at 06:45:34PM +0900, Jinwook Jeong wrote:

quoted

1. `cd` into any git repo that has at least one commit.
2. Identify the current branch, say main
3. $ git branch foo # a new branch
4. $ git worktree add ../new_worktree foo
5. $ cd ../new_worktree
6. $ git checkout -B master HEAD

Was your intention to get this worktree's content back to what is in
master's HEAD?, then the command should had been

$ git reset --hard master

The documentation might be confusing, but you most likely do NOT want
to use -B unless you want to force things, but the lowercase version `-b`

quoted

Anything else you want to add:

https://www.git-scm.com/docs/git-checkout#Documentation/git-checkout.txt-emgitcheckoutem-b-Bltnew-branchgtltstart-pointgt

According to the documentation, "git checkout -B BRANCH START" is the
transactionally equivalent of:

  git branch -f BRANCH START
  git checkout BRANCH

When I ran the first command in place of the step 6 of the above
reproducing procedure, git refused to carry on;
I suppose that this is the intended behavior for "git checkout -B".

I think you are correct, and this is therefore a bug, but there is also
a reason why `--force` allows doing dangerous things and I am not sure
if it might apply here.

I'd say there's a bug in `git-switch/git-checkout -B` not performing
the same checks as `git branch -f`. As a result, it is possible to get
into a state in which the same branch is checked out in multiple
worktrees, which is probably undesirable. I looked briefly through the
code but don't have the time presently to dig into it.