thodg/libgit2

diff --git a/src/commit.c b/src/commit.c
index a3baf9d..5acbbc3 100644
--- a/src/commit.c
+++ b/src/commit.c
@@ -229,19 +229,25 @@ GIT_COMMIT_GETTER(int, time_offset, commit->committer->when.offset)
 GIT_COMMIT_GETTER(unsigned int, parentcount, commit->parent_oids.length)
 GIT_COMMIT_GETTER(const git_oid *, tree_oid, &commit->tree_oid);
 
-
 int git_commit_tree(git_tree **tree_out, git_commit *commit)
 {
 	assert(commit);
 	return git_tree_lookup(tree_out, commit->object.repo, &commit->tree_oid);
 }
 
+const git_oid *git_commit_parent_oid(git_commit *commit, unsigned int n)
+{
+	assert(commit);
+
+	return git_vector_get(&commit->parent_oids, n);
+}
+
 int git_commit_parent(git_commit **parent, git_commit *commit, unsigned int n)
 {
-	git_oid *parent_oid;
+	const git_oid *parent_oid;
 	assert(commit);
 
-	parent_oid = git_vector_get(&commit->parent_oids, n);
+	parent_oid = git_commit_parent_oid(commit, n);
 	if (parent_oid == NULL) {
 		giterr_set(GITERR_INVALID, "Parent %u does not exist", n);
 		return GIT_ENOTFOUND;
@@ -249,10 +255,3 @@ int git_commit_parent(git_commit **parent, git_commit *commit, unsigned int n)
 
 	return git_commit_lookup(parent, commit->object.repo, parent_oid);
 }
-
-const git_oid *git_commit_parent_oid(git_commit *commit, unsigned int n)
-{
-	assert(commit);
-
-	return git_vector_get(&commit->parent_oids, n);
-}