thodg/libgit2

diff --git a/src/commit.c b/src/commit.c
index 227d5c4..78c4b9d 100644
--- a/src/commit.c
+++ b/src/commit.c
@@ -16,6 +16,7 @@
 #include "commit.h"
 #include "signature.h"
 #include "message.h"
+#include "refs.h"
 
 void git_commit__free(void *_commit)
 {
@@ -34,35 +35,6 @@ void git_commit__free(void *_commit)
 	git__free(commit);
 }
 
-static int update_ref_for_commit(git_repository *repo, git_reference *ref, const char *update_ref, const git_oid *id, const git_signature *committer)
-{
-	git_reference *ref2 = NULL;
-	int error;
-	git_commit *c;
-	const char *shortmsg;
-	git_buf reflog_msg = GIT_BUF_INIT;
-
-	if ((error = git_commit_lookup(&c, repo, id)) < 0) {
-		return error;
-	}
-
-	shortmsg = git_commit_summary(c);
-	git_buf_printf(&reflog_msg, "commit%s: %s",
-		       git_commit_parentcount(c) == 0 ? " (initial)" : "",
-		       shortmsg);
-	git_commit_free(c);
-
-	if (ref) {
-		error = git_reference_set_target(&ref2, ref, id, committer, git_buf_cstr(&reflog_msg));
-		git_reference_free(ref2);
-	} else {
-		error = git_reference__update_terminal(repo, update_ref, id, committer, git_buf_cstr(&reflog_msg));
-	}
-
-	git_buf_free(&reflog_msg);
-	return error;
-}
-
 int git_commit_create_from_callback(
 	git_oid *id,
 	git_repository *repo,
@@ -131,7 +103,8 @@ int git_commit_create_from_callback(
 	git_buf_free(&commit);
 
 	if (update_ref != NULL) {
-		error = update_ref_for_commit(repo, ref, update_ref, id, committer);
+		error = git_reference__update_for_commit(
+			repo, ref, update_ref, id, committer, "commit");
 		git_reference_free(ref);
 		return error;
 	}
@@ -321,7 +294,8 @@ int git_commit_amend(
 		&tree_id, commit_parent_for_amend, (void *)commit_to_amend);
 
 	if (!error && update_ref) {
-		error = update_ref_for_commit(repo, ref, NULL, id, committer);
+		error = git_reference__update_for_commit(
+			repo, ref, NULL, id, committer, "commit");
 		git_reference_free(ref);
 	}
 
diff --git a/src/rebase.c b/src/rebase.c
index 101dfb1..60c3dd0 100644
--- a/src/rebase.c
+++ b/src/rebase.c
@@ -686,10 +686,11 @@ static int rebase_commit_merge(
 {
 	git_index *index = NULL;
 	git_reference *head = NULL;
-	git_commit *head_commit = NULL;
+	git_commit *head_commit = NULL, *commit = NULL;
 	git_tree *head_tree = NULL, *tree = NULL;
 	git_diff *diff = NULL;
 	git_oid tree_id;
+	git_buf reflog_msg = GIT_BUF_INIT;
 	char old_idstr[GIT_OID_HEXSZ], new_idstr[GIT_OID_HEXSZ];
 	int error;
 
@@ -732,9 +733,12 @@ static int rebase_commit_merge(
 		message = git_commit_message(state->merge.current);
 	}
 
-	if ((error = git_commit_create(commit_id, repo, "HEAD", author,
+	if ((error = git_commit_create(commit_id, repo, NULL, author,
 			committer, message_encoding, message, tree, 1,
-			(const git_commit **)&head_commit)) < 0)
+			(const git_commit **)&head_commit)) < 0 ||
+		(error = git_commit_lookup(&commit, repo, commit_id)) < 0 ||
+		(error = git_reference__update_for_commit(
+			repo, NULL, "HEAD", commit_id, committer, "rebase")) < 0)
 		goto done;
 
 	git_oid_fmt(old_idstr, git_commit_id(state->merge.current));
@@ -744,6 +748,8 @@ static int rebase_commit_merge(
 		"%.*s %.*s\n", GIT_OID_HEXSZ, old_idstr, GIT_OID_HEXSZ, new_idstr);
 
 done:
+	git_buf_free(&reflog_msg);
+	git_commit_free(commit);
 	git_diff_free(diff);
 	git_tree_free(tree);
 	git_tree_free(head_tree);
diff --git a/src/refs.c b/src/refs.c
index 08e407e..43c7333 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -22,6 +22,7 @@
 #include <git2/refdb.h>
 #include <git2/sys/refs.h>
 #include <git2/signature.h>
+#include <git2/commit.h>
 
 GIT__USE_STRMAP;
 
@@ -1090,6 +1091,40 @@ int git_reference__update_terminal(
 	return reference__update_terminal(repo, ref_name, oid, 0, signature, log_message);
 }
 
+int git_reference__update_for_commit(
+	git_repository *repo,
+	git_reference *ref,
+	const char *ref_name,
+	const git_oid *id,
+	const git_signature *committer,
+	const char *operation)
+{
+	git_reference *ref_new = NULL;
+	git_commit *commit = NULL;
+	git_buf reflog_msg = GIT_BUF_INIT;
+	int error;
+
+	if ((error = git_commit_lookup(&commit, repo, id)) < 0 ||
+		(error = git_buf_printf(&reflog_msg, "%s%s: %s",
+			operation ? operation : "commit",
+			git_commit_parentcount(commit) == 0 ? " (initial)" : "",
+			git_commit_summary(commit))) < 0)
+		goto done;
+
+	if (ref)
+		error = git_reference_set_target(
+			&ref_new, ref, id, committer, git_buf_cstr(&reflog_msg));
+	else
+		error = git_reference__update_terminal(
+			repo, ref_name, id, committer, git_buf_cstr(&reflog_msg));
+
+done:
+	git_reference_free(ref_new);
+	git_buf_free(&reflog_msg);
+	git_commit_free(commit);
+	return error;
+}
+
 int git_reference_has_log(git_repository *repo, const char *refname)
 {
 	int error;
diff --git a/src/refs.h b/src/refs.h
index c6ec429..5f48efc 100644
--- a/src/refs.h
+++ b/src/refs.h
@@ -100,4 +100,13 @@ int git_reference_lookup_resolved(
 
 int git_reference__log_signature(git_signature **out, git_repository *repo);
 
+/** Update a reference after a commit. */
+int git_reference__update_for_commit(
+	git_repository *repo,
+	git_reference *ref,
+	const char *ref_name,
+	const git_oid *id,
+	const git_signature *committer,
+	const char *operation);
+
 #endif
diff --git a/tests/rebase/merge.c b/tests/rebase/merge.c
index fa37e89..0d4dca4 100644
--- a/tests/rebase/merge.c
+++ b/tests/rebase/merge.c
@@ -178,6 +178,8 @@ void test_rebase_merge__commit(void)
 	git_oid commit_id, tree_id, parent_id;
 	git_signature *author;
 	git_commit *commit;
+	git_reflog *reflog;
+	const git_reflog_entry *reflog_entry;
 
 	checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE;
 
@@ -211,8 +213,14 @@ void test_rebase_merge__commit(void)
 
 	cl_assert(git_signature__equal(signature, git_commit_committer(commit)));
 
-	cl_assert_equal_file("da9c51a23d02d931a486f45ad18cda05cf5d2b94 776e4c48922799f903f03f5f6e51da8b01e4cce0\n", 82, "rebase/.git/rebase-merge/rewritten");
+	/* Make sure the reflogs are updated appropriately */
+	cl_git_pass(git_reflog_read(&reflog, repo, "HEAD"));
+	cl_assert(reflog_entry = git_reflog_entry_byindex(reflog, 0));
+	cl_assert_equal_oid(&parent_id, git_reflog_entry_id_old(reflog_entry));
+	cl_assert_equal_oid(&commit_id, git_reflog_entry_id_new(reflog_entry));
+	cl_assert_equal_s("rebase: Modification 1 to beef", git_reflog_entry_message(reflog_entry));
 
+	git_reflog_free(reflog);
 	git_signature_free(author);
 	git_commit_free(commit);
 	git_merge_head_free(branch_head);