append_one_rev(): rewrite to work with object_id

diff --git a/t/t2011-checkout-invalid-head.sh b/t/t2011-checkout-invalid-head.sh
index 15ebdc26ebaaf7881b1f51eb788c2eb2922b6d4f..300f8bf25c34cf4ea4e011d1daa525285ca94c5a 100755 (executable)
--- a/t/t2011-checkout-invalid-head.sh
+++ b/t/t2011-checkout-invalid-head.sh
@@ -15,7 +15,7 @@ test_expect_success 'checkout should not start branch from a tree' '
 '
 
 test_expect_success 'checkout master from invalid HEAD' '
-       echo 0000000000000000000000000000000000000000 >.git/HEAD &&
+       echo $_z40 >.git/HEAD &&
        git checkout master --
 '