Show bug

git clone git@github.com:nicerobot/go-git-bug-linked-worktrees
cd go-git-bug-linked-worktrees
make

Output

$ make
git clone git@github.com:src-d/go-git.git
Cloning into 'go-git'...
cd go-git; git fetch --all
go-git-bug/go-git
Fetching origin
cd go-git; git worktree add -b new-ref ../go-git-linked/
go-git-bug/go-git
Preparing worktree (new branch 'new-ref')
HEAD is now at 1a7db85bca70 Merge pull request #1231 from alexandear/fix-typos
go build -o bugged


---- Works as expected
go-git-bug/go-git
git rev-parse --git-dir
.git
git rev-parse HEAD
1a7db85bca7027d90afdb5ce711622aaac9feaed
2019/12/01 11:39:36 worktree: go-git-bug/go-git
2019/12/01 11:39:36 1a7db85bca7027d90afdb5ce711622aaac9feaed refs/heads/master
2019/12/01 11:39:36 1a7db85bca7027d90afdb5ce711622aaac9feaed refs/heads/new-ref
2019/12/01 11:39:36 head: 1a7db85bca7027d90afdb5ce711622aaac9feaed refs/heads/master


---- Bug this does not work as expected
go-git-bug/go-git-linked
git rev-parse --git-dir
go-git-bug/go-git/.git/worktrees/go-git-linked
git rev-parse HEAD
1a7db85bca7027d90afdb5ce711622aaac9feaed
2019/12/01 11:39:36 worktree: go-git-bug/go-git-linked
2019/12/01 11:39:36 head: reference not found
make: *** [bug] Error 1

Call-stack

repo, err := git.PlainOpenWithOptions(".", &git.PlainOpenOptions{DetectDotGit: true})
repo.Head()
storer.ResolveReference(r.Storer, plumbing.HEAD)
resolveReference(s, r, 0)
s.Reference(r.Target())
r.dir.Ref(n) // <- `n` (i.e. `r.Target()`) is `ref/heads/new-ref`
d.readReferenceFile(".", name.String())
d.fs.Open(path) // <- this `path` is wrong for this situation