untracked-cache: be defensive about missing NULs in index

diff --git a/t/t4254-am-corrupt.sh b/t/t4254-am-corrupt.sh
index 168739c7214c764ef7f35a83063d369c1db22ec4..fd3bdbfe2c0a30a0b712b1a59c2bacf0efde167c 100755 (executable)
--- a/t/t4254-am-corrupt.sh
+++ b/t/t4254-am-corrupt.sh
@@ -25,7 +25,7 @@ test_expect_success setup '
 #   fatal: unable to write file '(null)' mode 100644: Bad address
 # Also, it had the unwanted side-effect of deleting f.
 test_expect_success 'try to apply corrupted patch' '
-       test_must_fail git am bad-patch.diff 2>actual
+       test_must_fail git -c advice.amWorkDir=false am bad-patch.diff 2>actual
 '
 
 test_expect_success 'compare diagnostic; ensure file is still here' '