Clone can't checkout commit pointed to by tag, but Git works #574
Description
If a tag is created pointing to a commit that hasn't been pushed yet, then the checkout will error. However, git works, and the commit is browse-able on GitHub. However, you can see its not in the commit history at all.
The only reason this feels like a bug to me is really because git show <tag> and git checkout <tag> somehow work despite the commit not being easily viewable in any other way.
I created a test repository to reproduce this: https://github.com/mitchellh/go-git-test-failure
Notice the tag v0.1.0 points to a commit (you can click it and see it), but if you go to the commit history it doesn't exist, and there are no other branches either. This is a lightweight tag. But clone the repository manually and you'll be able to use that tag with git.
And some code you can run with go run to reproduce this:
package main
import (
"fmt"
"io/ioutil"
"os"
"gopkg.in/src-d/go-git.v4"
"gopkg.in/src-d/go-git.v4/plumbing"
)
func main() {
// Create the temporary directory for cloning
dir, err := ioutil.TempDir("", "test")
if err != nil {
panic(err)
}
// Clone it into the target directory getting only the tag commit
repo, err := git.PlainClone(dir, false, &git.CloneOptions{
URL: "https://github.com/mitchellh/go-git-test-failure.git",
})
if err != nil {
os.RemoveAll(dir)
panic(err)
}
// Get the working tree so we can change refs
tree, err := repo.Worktree()
if err != nil {
panic(err)
}
tagName := "v0.1.0"
// Checkout our tag
err = tree.Checkout(&git.CheckoutOptions{
Branch: plumbing.ReferenceName("refs/tags/" + tagName),
})
if err != nil {
panic(err)
}
fmt.Println(dir)
}