remote: fix push delete, closes #466

Refspecs for deletes were not being used to produce
delete commands on the update request.

2 files changed, 95 insertions, 12 deletions

diff --git a/remote.go b/remote.go
index 412eb61..9bc31ff 100644
--- a/remote.go
+++ b/remote.go
@@ -238,24 +238,60 @@ func (r *Remote) addReferencesToUpdate(refspecs []config.RefSpec,
 	req *packp.ReferenceUpdateRequest) error {
 
 	for _, rs := range refspecs {
-		iter, err := r.s.IterReferences()
-		if err != nil {
-			return err
-		}
-
-		err = iter.ForEach(func(ref *plumbing.Reference) error {
-			return r.addReferenceIfRefSpecMatches(
-				rs, remoteRefs, ref, req,
-			)
-		})
-		if err != nil {
-			return err
+		if rs.IsDelete() {
+			if err := r.deleteReferences(rs, remoteRefs, req); err != nil {
+				return err
+			}
+		} else {
+			if err := r.addOrUpdateReferences(rs, remoteRefs, req); err != nil {
+				return err
+			}
 		}
 	}
 
 	return nil
 }
 
+func (r *Remote) addOrUpdateReferences(rs config.RefSpec,
+	remoteRefs storer.ReferenceStorer, req *packp.ReferenceUpdateRequest) error {
+	iter, err := r.s.IterReferences()
+	if err != nil {
+		return err
+	}
+
+	return iter.ForEach(func(ref *plumbing.Reference) error {
+		return r.addReferenceIfRefSpecMatches(
+			rs, remoteRefs, ref, req,
+		)
+	})
+}
+
+func (r *Remote) deleteReferences(rs config.RefSpec,
+	remoteRefs storer.ReferenceStorer, req *packp.ReferenceUpdateRequest) error {
+	iter, err := remoteRefs.IterReferences()
+	if err != nil {
+		return err
+	}
+
+	return iter.ForEach(func(ref *plumbing.Reference) error {
+		if ref.Type() != plumbing.HashReference {
+			return nil
+		}
+
+		if rs.Dst("") != ref.Name() {
+			return nil
+		}
+
+		cmd := &packp.Command{
+			Name: ref.Name(),
+			Old: ref.Hash(),
+			New: plumbing.ZeroHash,
+		}
+		req.Commands = append(req.Commands, cmd)
+		return nil
+	})
+}
+
 func (r *Remote) addReferenceIfRefSpecMatches(rs config.RefSpec,
 	remoteRefs storer.ReferenceStorer, localRef *plumbing.Reference,
 	req *packp.ReferenceUpdateRequest) error {
diff --git a/remote_test.go b/remote_test.go
index 4297b81..c12d5d5 100644
--- a/remote_test.go
+++ b/remote_test.go
@@ -5,6 +5,8 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"path/filepath"
+	"strings"
 
 	"github.com/src-d/go-git-fixtures"
 	"gopkg.in/src-d/go-git.v4/config"
@@ -334,6 +336,32 @@ func (s *RemoteSuite) TestPushNoErrAlreadyUpToDate(c *C) {
 	c.Assert(err, Equals, NoErrAlreadyUpToDate)
 }
 
+func (s *RemoteSuite) TestPushDeleteReference(c *C) {
+	f := fixtures.Basic().One()
+	sto, err := filesystem.NewStorage(f.DotGit())
+	c.Assert(err, IsNil)
+
+	dstFs := f.DotGit()
+	dstSto, err := filesystem.NewStorage(dstFs)
+	c.Assert(err, IsNil)
+	prepareRepo(c, dstFs.Root())
+
+	url := dstFs.Root()
+	r := newRemote(sto, &config.RemoteConfig{
+		Name: DefaultRemoteName,
+		URL:  url,
+	})
+
+	rs := config.RefSpec(":refs/heads/branch")
+	err = r.Push(&PushOptions{
+		RefSpecs: []config.RefSpec{rs},
+	})
+	c.Assert(err, IsNil)
+
+	_, err = dstSto.Reference(plumbing.ReferenceName("refs/heads/branch"))
+	c.Assert(err, Equals, plumbing.ErrReferenceNotFound)
+}
+
 func (s *RemoteSuite) TestPushRejectNonFastForward(c *C) {
 	f := fixtures.Basic().One()
 	sto, err := filesystem.NewStorage(f.DotGit())
@@ -470,3 +498,22 @@ func (s *RemoteSuite) TestPushWrongRemoteName(c *C) {
 	})
 	c.Assert(err, ErrorMatches, ".*remote names don't match.*")
 }
+
+const bareConfig = `[core]
+repositoryformatversion = 0
+filemode = true
+bare = true`
+
+func prepareRepo(c *C, path string) {
+	// git-receive-pack refuses to update refs/heads/master on non-bare repo
+	// so we ensure bare repo config.
+	config := filepath.Join(path, "config")
+	if _, err := os.Stat(config); err == nil {
+		f, err := os.OpenFile(config, os.O_TRUNC|os.O_WRONLY, 0)
+		c.Assert(err, IsNil)
+		content := strings.NewReader(bareConfig)
+		_, err = io.Copy(f, content)
+		c.Assert(err, IsNil)
+		c.Assert(f.Close(), IsNil)
+	}
+}