refs: honor strict object creation

src/refs.c

@@ -377,15 +377,9 @@ static int reference__create(
 		return error;
 
 	if (oid != NULL) {
-		git_odb *odb;
-
 		assert(symbolic == NULL);
 
-		/* Sanity check the reference being created - target must exist. */
-		if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
-			return error;
-
-		if (!git_odb_exists(odb, oid)) {
+		if (!git_object__is_valid(repo, oid, GIT_OBJ_ANY)) {
 			giterr_set(GITERR_REFERENCE,
 				"Target OID for the reference doesn't exist on the repository");
 			return -1;

tests/refs/create.c

@@ -18,6 +18,8 @@ void test_refs_create__initialize(void)
 void test_refs_create__cleanup(void)
 {
    cl_git_sandbox_cleanup();
+
+	cl_git_pass(git_libgit2_opts(GIT_OPT_ENABLE_STRICT_OBJECT_CREATION, 0));
 }
 
 void test_refs_create__symbolic(void)
@@ -119,9 +121,27 @@ void test_refs_create__oid(void)
 	git_reference_free(looked_up_ref);
 }
 
-void test_refs_create__oid_unknown(void)
+/* Can by default create a reference that targets at an unknown id */
+void test_refs_create__oid_unknown_succeeds_by_default(void)
+{
+	git_reference *new_reference, *looked_up_ref;
+	git_oid id;
+
+	const char *new_head = "refs/heads/new-head";
+
+	git_oid_fromstr(&id, "deadbeef3f795b2b4353bcce3a527ad0a4f7f644");
+
+	/* Create and write the new object id reference */
+	cl_git_pass(git_reference_create(&new_reference, g_repo, new_head, &id, 0, NULL));
+
+	/* Ensure the reference can't be looked-up... */
+	cl_git_pass(git_reference_lookup(&looked_up_ref, g_repo, new_head));
+	git_reference_free(looked_up_ref);
+}
+
+/* Strict object enforcement enforces valid object id */
+void test_refs_create__oid_unknown_fails_strict_mode(void)
 {
-   // Can not create a new OID reference which targets at an unknown id
 	git_reference *new_reference, *looked_up_ref;
 	git_oid id;
 
@@ -129,6 +149,8 @@ void test_refs_create__oid_unknown(void)
 
 	git_oid_fromstr(&id, "deadbeef3f795b2b4353bcce3a527ad0a4f7f644");
 
+	cl_git_pass(git_libgit2_opts(GIT_OPT_ENABLE_STRICT_OBJECT_CREATION, 1));
+
 	/* Create and write the new object id reference */
 	cl_git_fail(git_reference_create(&new_reference, g_repo, new_head, &id, 0, NULL));