test_expect_success 'diff-tree between trees' '
        {
-               printf ":000000 100644 $_z40 $blob_two A\touter/inner\n" &&
-               printf ":000000 100644 $_z40 $blob_two A\touter/inner\n" &&
-               printf ":000000 100644 $_z40 $blob_two A\touter/inner\n" &&
-               printf ":100644 000000 $blob_two $_z40 D\touter/inner\n" &&
-               printf ":100644 000000 $blob_two $_z40 D\touter/inner\n" &&
-               printf ":100644 000000 $blob_two $_z40 D\touter/inner\n"
+               printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
+               printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
+               printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
+               printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+               printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+               printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n"
        } >expect &&
        git diff-tree -r --no-abbrev one two >actual &&
        test_cmp expect actual