Merge pull request #534 from josharian/firstparent

plumbing: object, commit.Parent() method

1 files changed, 12 insertions, 0 deletions

diff --git a/plumbing/object/commit.go b/plumbing/object/commit.go
index fad3dac..b2f1f15 100644
--- a/plumbing/object/commit.go
+++ b/plumbing/object/commit.go
@@ -3,6 +3,7 @@ package object
 import (
 	"bufio"
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"strings"
@@ -98,6 +99,17 @@ func (c *Commit) NumParents() int {
 	return len(c.ParentHashes)
 }
 
+var ErrParentNotFound = errors.New("commit parent not found")
+
+// Parent returns the ith parent of a commit.
+func (c *Commit) Parent(i int) (*Commit, error) {
+	if len(c.ParentHashes) == 0 || i > len(c.ParentHashes)-1 {
+		return nil, ErrParentNotFound
+	}
+
+	return GetCommit(c.s, c.ParentHashes[i])
+}
+
 // File returns the file with the specified "path" in the commit and a
 // nil error if the file exists. If the file does not exist, it returns
 // a nil file and the ErrFileNotFound error.