Using the reference instead of the hash to describe

Signed-off-by: Eduardo Lezcano <eduardo.lezcano@be.atlascopco.com>

Author: Eduardo Lezcano

repository.go

@@ -1253,7 +1253,7 @@ type DescribeOptions struct {
 
 type Describe struct {
 	// Reference being described
-	Hash *plumbing.Hash
+	Reference *plumbing.Reference
 	// Tag of the describe object
 	Tag *plumbing.Reference
 	// Distance to the tag object in commits
@@ -1266,17 +1266,17 @@ func (d *Describe) String() string {
 	return fmt.Sprintf("%v-%v-%v-%v",
 		d.Tag.Name().Short(),
 		d.Distance,
-		d.Hash.String()[0:8],
+		d.Reference.Hash().String()[0:8],
 		d.Dirty)
 }
 
 // Describe just like the `git describe` command will return a Describe struct for the hash passed.
 // Describe struct implements String interface so it can be easily printed out.
-func (r *Repository) Describe(options *DescribeOptions, hash *plumbing.Hash) (*Describe, error) {
+func (r *Repository) Describe(ref *plumbing.Reference, options *DescribeOptions) (*Describe, error) {
 
 	// Fetch the reference log
 	commitIterator, err := r.Log(&LogOptions{
-		From:  *hash,
+		From:  ref.Hash(),
 		Order: LogOrderCommitterTime,
 	})
 	if err != nil {
@@ -1310,7 +1310,7 @@ func (r *Repository) Describe(options *DescribeOptions, hash *plumbing.Hash) (*D
 	})
 
 	return &Describe{
-		hash,
+		ref,
 		tag,
 		count,
 		options.Dirty,