Added git_commit_tree_oid and git_commit_parent_oid.

include/git2/commit.h

@@ -136,6 +136,16 @@ GIT_EXTERN(const git_signature *) git_commit_author(git_commit *commit);
 GIT_EXTERN(int) git_commit_tree(git_tree **tree_out, git_commit *commit);
 
 /**
+ * Get the id of the tree pointed to by a commit. This differs from
+ * `git_commit_tree` in that no attempts are made to fetch an object
+ * from the ODB.
+ *
+ * @param commit a previously loaded commit.
+ * @return the id of tree pointed to by commit.
+ */
+GIT_EXTERN(const git_oid *) git_commit_tree_oid(git_commit *commit);
+
+/**
  * Get the number of parents of this commit
  *
  * @param commit a previously loaded commit.
@@ -153,6 +163,16 @@ GIT_EXTERN(unsigned int) git_commit_parentcount(git_commit *commit);
  */
 GIT_EXTERN(int) git_commit_parent(git_commit **parent, git_commit *commit, unsigned int n);
 
+/**
+ * Get the oid of a specified parent for a commit. This is different from
+ * `git_commit_parent`, which will attempt to load the parent commit from
+ * the ODB.
+ *
+ * @param commit a previously loaded commit.
+ * @param n the position of the parent (from 0 to `parentcount`)
+ * @return the id of the parent, NULL on error.
+ */
+GIT_EXTERN(const git_oid *) git_commit_parent_oid(git_commit *commit, unsigned int n);
 
 /**
  * Create a new commit in the repository

src/commit.c

@@ -318,6 +318,7 @@ GIT_COMMIT_GETTER(const char *, message_short, commit->message_short)
 GIT_COMMIT_GETTER(git_time_t, time, commit->committer->when.time)
 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)
@@ -338,4 +339,9 @@ 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);
+}