grep: enable recurse-submodules to work on <tree> objects

diff --git a/t/t3700-add.sh b/t/t3700-add.sh
index 53c0cb6dea686ac872c219b746a0c24b3d505416..f3a4b4a913f344ce140344ec7b70482a6d36bcbe 100755 (executable)
--- a/t/t3700-add.sh
+++ b/t/t3700-add.sh
@@ -331,6 +331,11 @@ test_expect_success 'git add --dry-run --ignore-missing of non-existing file out
        test_i18ncmp expect.err actual.err
 '
 
+test_expect_success 'git add empty string should invoke warning' '
+       git add "" 2>output &&
+       test_i18ngrep "warning: empty strings" output
+'
+
 test_expect_success 'git add --chmod=[+-]x stages correctly' '
        rm -f foo1 &&
        echo foo >foo1 &&