[WIP] git: Add support to list peeled refs

Signed-off-by: Paulo Gomes <pjbgf@linux.com>

_examples/ls-remote/main.go

@@ -11,16 +11,20 @@ import (
 // Retrieve remote tags without cloning repository
 func main() {
 
+	url := "https://github.com/aide/aide"
+
 	// Create the remote with repository URL
 	rem := git.NewRemote(memory.NewStorage(), &config.RemoteConfig{
 		Name: "origin",
-		URLs: []string{"https://github.com/Zenika/MARCEL"},
+		URLs: []string{url},
 	})
 
 	log.Print("Fetching tags...")
 
 	// We can then use every Remote functions to retrieve wanted information
-	refs, err := rem.List(&git.ListOptions{})
+	refs, err := rem.List(&git.ListOptions{
+		PeelOption: git.PeelOnly,
+	})
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -29,6 +33,7 @@ func main() {
 	var tags []string
 	for _, ref := range refs {
 		if ref.Name().IsTag() {
+			log.Printf("%s: %s\n", ref.Name(), ref.Hash())
 			tags = append(tags, ref.Name().Short())
 		}
 	}
@@ -37,6 +42,4 @@ func main() {
 		log.Println("No tags!")
 		return
 	}
-
-	log.Printf("Tags found: %v", tags)
 }

options.go

@@ -624,8 +624,22 @@ type ListOptions struct {
 	InsecureSkipTLS bool
 	// CABundle specify additional ca bundle with system cert pool
 	CABundle []byte
+
+	// PeelOption defines how peeled refs will be handled.
+	PeelOption PeelOption
 }
 
+type PeelOption uint8
+
+const (
+	// PeelIgnore ignores all peeled refs. This is the default.
+	PeelIgnore PeelOption = 0
+	// PeelOnly returns only peeled refs and ignores the rest.
+	PeelOnly PeelOption = 1
+	// PeelBoth returns peeled refs together with the other refs.
+	PeelBoth PeelOption = 2
+)
+
 // CleanOptions describes how a clean should be performed.
 type CleanOptions struct {
 	Dir bool

remote.go

@@ -1282,13 +1282,22 @@ func (r *Remote) list(ctx context.Context, o *ListOptions) (rfs []*plumbing.Refe
 	}
 
 	var resultRefs []*plumbing.Reference
-	err = refs.ForEach(func(ref *plumbing.Reference) error {
-		resultRefs = append(resultRefs, ref)
-		return nil
-	})
-	if err != nil {
-		return nil, err
+	if o.PeelOption == PeelBoth || o.PeelOption == PeelIgnore {
+		err = refs.ForEach(func(ref *plumbing.Reference) error {
+			resultRefs = append(resultRefs, ref)
+			return nil
+		})
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if o.PeelOption == PeelBoth || o.PeelOption == PeelOnly {
+		for k, v := range ar.Peeled {
+			resultRefs = append(resultRefs, plumbing.NewReferenceFromStrings(k+"^{}", v.String()))
+		}
 	}
+
 	return resultRefs, nil
 }