read-tree A B C: do not create a bogus index and do not segfault

diff --git a/t/t4027-diff-submodule.sh b/t/t4027-diff-submodule.sh
index 61caad0f5d4bea470226daf60780066abc99e5d3..ba6679c6e4032bb12e4206226f95770946ece8cc 100755 (executable)
--- a/t/t4027-diff-submodule.sh
+++ b/t/t4027-diff-submodule.sh
@@ -50,7 +50,7 @@ test_expect_success 'git diff-files --raw' '
        test_cmp expect actual.files
 '
 
-test_expect_failure 'git diff (empty submodule dir)' '
+test_expect_success 'git diff (empty submodule dir)' '
        : >empty &&
        rm -rf sub/* sub/.git &&
        git diff > actual.empty &&