untracked-cache: be defensive about missing NULs in index

diff --git a/t/t7011-skip-worktree-reading.sh b/t/t7011-skip-worktree-reading.sh
index 84f41451ec4e34b6438313545ca886fbef75f34d..37525cae3af303dd60531226d885c72725b0ae53 100755 (executable)
--- a/t/t7011-skip-worktree-reading.sh
+++ b/t/t7011-skip-worktree-reading.sh
@@ -118,7 +118,7 @@ test_expect_success 'grep with skip-worktree file' '
        test "$(git grep --no-ext-grep test)" = "1:test"
 '
 
-echo ":000000 100644 $_z40 $EMPTY_BLOB A       1" > expected
+echo ":000000 100644 $ZERO_OID $EMPTY_BLOB A   1" > expected
 test_expect_success 'diff-index does not examine skip-worktree absent entries' '
        setup_absent &&
        git diff-index HEAD -- 1 > result &&