Merge pull request libgit2#3757 from johnhaley81/jh/fix-create-initial-commit

Fix `git_commit_create` for an initial commit

Author: carlosmn

src/commit.c

@@ -104,7 +104,7 @@ static int validate_tree_and_parents(git_array_oid_t *parents, git_repository *r
 		i++;
 	}
 
-	if (current_id && git_oid_cmp(current_id, git_array_get(*parents, 0))) {
+	if (current_id && (parents->size == 0 || git_oid_cmp(current_id, git_array_get(*parents, 0)))) {
 		giterr_set(GITERR_OBJECT, "failed to create commit: current tip is not the first parent");
 		error = GIT_EMODIFIED;
 		goto on_error;

tests/commit/commit.c

@@ -51,6 +51,66 @@ void test_commit_commit__create_unexisting_update_ref(void)
 	git_reference_free(ref);
 }
 
+void test_commit_commit__create_initial_commit(void)
+{
+	git_oid oid;
+	git_tree *tree;
+	git_commit *commit;
+	git_signature *s;
+	git_reference *ref;
+
+	git_oid_fromstr(&oid, "a65fedf39aefe402d3bb6e24df4d4f5fe4547750");
+	cl_git_pass(git_commit_lookup(&commit, _repo, &oid));
+
+	git_oid_fromstr(&oid, "944c0f6e4dfa41595e6eb3ceecdb14f50fe18162");
+	cl_git_pass(git_tree_lookup(&tree, _repo, &oid));
+
+	cl_git_pass(git_signature_now(&s, "alice", "alice@example.com"));
+
+	cl_git_fail(git_reference_lookup(&ref, _repo, "refs/heads/foo/bar"));
+	cl_git_pass(git_commit_create(&oid, _repo, "refs/heads/foo/bar", s, s,
+				      NULL, "initial commit", tree, 0, NULL));
+
+	cl_git_pass(git_reference_lookup(&ref, _repo, "refs/heads/foo/bar"));
+
+	cl_assert_equal_oid(&oid, git_reference_target(ref));
+
+	git_tree_free(tree);
+	git_commit_free(commit);
+	git_signature_free(s);
+	git_reference_free(ref);
+}
+
+void test_commit_commit__create_initial_commit_parent_not_current(void)
+{
+	git_oid oid;
+	git_oid original_oid;
+	git_tree *tree;
+	git_commit *commit;
+	git_signature *s;
+
+	git_oid_fromstr(&oid, "a65fedf39aefe402d3bb6e24df4d4f5fe4547750");
+	cl_git_pass(git_commit_lookup(&commit, _repo, &oid));
+
+	git_oid_fromstr(&oid, "944c0f6e4dfa41595e6eb3ceecdb14f50fe18162");
+	cl_git_pass(git_tree_lookup(&tree, _repo, &oid));
+
+	cl_git_pass(git_signature_now(&s, "alice", "alice@example.com"));
+
+	cl_git_pass(git_reference_name_to_id(&original_oid, _repo, "HEAD"));
+
+	cl_git_fail(git_commit_create(&oid, _repo, "HEAD", s, s,
+				      NULL, "initial commit", tree, 0, NULL));
+
+	cl_git_pass(git_reference_name_to_id(&oid, _repo, "HEAD"));
+
+	cl_assert_equal_oid(&oid, &original_oid);
+
+	git_tree_free(tree);
+	git_commit_free(commit);
+	git_signature_free(s);
+}
+
 void assert_commit_summary(const char *expected, const char *given)
 {
 	git_commit *dummy;