test-reach: test get_merge_bases_many

diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index faf0dfe993d375c885762b2d15706cd8ebe6d577..e1fd0f0ca8b5d731d79ccca1d6e6140683a3665f 100755 (executable)
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -6,7 +6,7 @@
 test_description='Test git update-ref and basic ref logging'
 . ./test-lib.sh
 
-Z=$_z40
+Z=$ZERO_OID
 
 m=refs/heads/master
 n_dir=refs/heads/gu