Pushing a repo on master works, but using references/branches seems to fail

[dbriesz]

Steps to reproduce:
• Add a downstream remote (r.CreateRemote)

• Push https://github.com/src-d/go-git.git-> works

• Push https://github.com/src-d/go-git.git/fix/checkout-empty-repo -> results in "already up-to-date"

Example code:

    // Add a downstream remote
    _, err = r.CreateRemote(&config.RemoteConfig{
        Name: "downstream",
        URLs: []string{"https://github.com/src-d/go-git.git"},
    })
    if err != nil {
        switch err {
        case git.ErrRemoteNotFound:
            log.Fatal("remote not found")
        default:
            log.Println(err)
        }
    }

    // Push using default options
    upstreamReference := plumbing.ReferenceName("refs/remotes/fix/checkout-empty-repo")
    downstreamReference := plumbing.ReferenceName("refs/remotes/fix/checkout-empty-repo")
    referenceList := append([]config.RefSpec{},
        config.RefSpec(upstreamReference+":"+downstreamReference))

    log.Printf("Pushing to https://github.com/src-d/go-git.git ...\n")
    err = r.Push(&git.PushOptions{
        RemoteName: "downstream",
        RefSpecs:   referenceList,
    })
    if err != nil {
        log.Fatal(err)
    } 

• Push with refs/heads usage also fails

Example code:

    // Add a downstream remote
    _, err = r.CreateRemote(&config.RemoteConfig{
        Name: "downstream",
        URLs: []string{"https://github.com/src-d/go-git.git"},
    })
    if err != nil {
        switch err {
        case git.ErrRemoteNotFound:
            log.Fatal("remote not found")
        default:
            log.Println(err)
        }
    }

    // Push using default options
    upstreamReference := plumbing.ReferenceName("refs/heads/fix/checkout-empty-repo")
    downstreamReference := plumbing.ReferenceName("refs/heads/fix/checkout-empty-repo")
    referenceList := append([]config.RefSpec{},
        config.RefSpec(upstreamReference+":"+downstreamReference))

    log.Printf("Pushing to https://github.com/src-d/go-git.git ...\n")
    err = r.Push(&git.PushOptions{
        RemoteName: "downstream",
        RefSpecs:   referenceList,
    })
    if err != nil {
        log.Fatal(err)
    } 

[orirawlings]

Hey @dbriesz,

If you get an "already up-to-date" it means that the reference on the remote already contains the commits you are trying to push. Unless you know for sure that there are changes locally on your fix/checkout-empty-repo that are not in the remote branch, this is expected behavior.

[dbriesz]

Hey @orirawlings,

Yes, I know for sure that local changes aren't in the remote branch since I'm trying to push a branch that I have locally to an empty remote branch

[orirawlings]

Hey @dbriesz,

I did some more troubleshooting on this. I'm not able to reproduce, although perhaps the error message is a little confusing when the branch you're trying to push does not exist either locally or on the remote (i.e. already up-to-date).

I'm running this code based on the latest changes in go-git/master:

$ cat main.go
package main

import (
	"fmt"
	"os"

	"gopkg.in/src-d/go-git.v4"
	. "gopkg.in/src-d/go-git.v4/_examples"
	"gopkg.in/src-d/go-git.v4/config"
	"gopkg.in/src-d/go-git.v4/plumbing"
)

// Open an existing repository in a specific folder.
func main() {
	CheckArgs("<path>")
	path := os.Args[1]

	r, err := git.PlainOpen(path)
	CheckIfError(err)

	ds, err := r.Remote("downstream")
	if err == git.ErrRemoteNotFound {
		ds, err = r.CreateRemote(&config.RemoteConfig{
			Name: "downstream",
			URLs: []string{"git@github.com:orirawlings/go-git-issues.git"},
		})
	}
	CheckIfError(err)

	b := plumbing.ReferenceName("refs/heads/fix/newBranch")

	// Check if reference exists locally
	refs, err := r.References()
	CheckIfError(err)
	var foundLocal bool
	CheckIfError(refs.ForEach(func(ref *plumbing.Reference) error {
		if ref.Name() == b {
			fmt.Printf("reference exists locally:\n%s\n", ref)
			foundLocal = true
		}
		return nil
	}))
	if !foundLocal {
		fmt.Printf("reference %s does not exist locally\n", b)
	}

	// Check if reference exists on remote
	remoteRefs, err := ds.List(&git.ListOptions{})
	CheckIfError(err)
	var found bool
	for _, ref := range remoteRefs {
		if ref.Name() == b {
			fmt.Printf("reference already exists on remote:\n%s\n", ref)
			found = true
		}
	}
	if !found {
		fmt.Printf("reference %s does not exist on remote\n", b)
	}

	// Push reference to remote
	CheckIfError(r.Push(&git.PushOptions{
		RemoteName: "downstream",
		RefSpecs: []config.RefSpec{
			config.RefSpec(b + ":" + b),
		},
	}))
}
$ git clone git@github.com:orirawlings/go-git-issues.git
Cloning into 'go-git-issues'...
remote: Counting objects: 21, done.
remote: Total 21 (delta 0), reused 0 (delta 0), pack-reused 21
Receiving objects: 100% (21/21), done.
Resolving deltas: 100% (5/5), done.

When I try the push without the branch locally or on the remote:

$ go run main.go go-git-issues/
reference refs/heads/fix/newBranch does not exist locally
reference refs/heads/fix/newBranch does not exist on remote
error: already up-to-date
exit status 1

When I create the branch locally and reattempt, the push succeeds without error:

$ git -C go-git-issues/ branch fix/newBranch master
$ go run main.go go-git-issues/
reference exists locally:
453962b0637a10461f40e14545940de0439770b4 refs/heads/fix/newBranch
reference refs/heads/fix/newBranch does not exist on remote

When I reattempt after both the local and remote have the branch:

$ go run main.go go-git-issues/
reference exists locally:
453962b0637a10461f40e14545940de0439770b4 refs/heads/fix/newBranch
reference already exists on remote:
453962b0637a10461f40e14545940de0439770b4 refs/heads/fix/newBranch
error: already up-to-date
exit status 1

In the specific example you posted above @dbriesz, the branch in question does exist on that particular git repository:

$ git ls-remote https://github.com/src-d/go-git.git | grep refs/heads/fix/checkout-empty-repo
92eff6678c1dd01bed17e4ab7bdf93b53b3bdffb        refs/heads/fix/checkout-empty-repo

So the trouble you are having might just be the particulars of the local and remote repository states.

I think something that would be a potential improvement here for go-git would be a better error message when you try to push a reference that does not exist locally. The standard git tooling gives a much more clear error in this scenario:

$ git -C go-git-issues/ push downstream refs/heads/doesNotExist:refs/heads/doesNotExist
error: src refspec refs/heads/doesNotExist does not match any.
error: failed to push some refs to 'git@github.com:orirawlings/go-git-issues.git'

[dbriesz]

Thanks @orirawlings. I'm trying a similar solution on my end, but I'm unable to get this code to work:

remoteRefs, err := ds.List(&git.ListOptions{})

This results in the error

ds.List undefined (type *git.Remote has no field or method List)

Is there another way to get a list of references from the Remote?

[orirawlings]

Sorry. I'm using a new feature in that example code that hasn't yet been published to the v4 branch. It is only available on go-git master.

[dbriesz]

Thanks - what is the proper way to use go-git master? I've tried go get -u github.com/src-d/go-git, but get an error that says package github.com/src-d/go-git ... expects import "gopkg.in/src-d/go-git.v4"

[orirawlings]

If you've retrieved the code using go get -u gopkg.in/src-d/go-git.v4/... then you can update it to the master branch by doing something like the following:

$ git -C $GOPATH/gopkg.in/src-d/go-git.v4 remote add github git@github.com:src-d/go-git.git
$ git -C $GOPATH/gopkg.in/src-d/go-git.v4 fetch github
$ git -C $GOPATH/gopkg.in/src-d/go-git.v4 checkout github/master  

[dbriesz]

Thanks, that worked! I had been using http.NewBasicAuth() in order to provide a username and password when the endpoint.Protocol() was https, but I don't see that function in master. Is there a way I can still do that when using master? For example, when I was using v4, I did something like this:

case endpoint.Protocol() == "https":
		auth := http.NewBasicAuth(username, password)
		return auth

Also, as an unrelated question, when might master be the new released version of go-git?

Thanks for your help!