When a user checks out the upstream branch of HEAD, the upstream branch
not being a local branch, and then runs "git status", like this:
git clone $URL client
cd client
git checkout @{u}
git status
no status is printed, but instead an error message:
fatal: HEAD does not point to a branch
(This error message when running "git branch" persists even after
checking out other things - it only stops after checking out a branch.)
This is because "git status" reads the reflog when determining the "HEAD
detached" message, and thus attempts to DWIM "@{u}", but that doesn't
work because HEAD no longer points to a branch.
Therefore, when calculating the status of a worktree, tolerate dangling
marks. This is done by adding an additional parameter to
dwim_ref() and repo_dwim_ref().
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>