diff-index.c: "git diff" has no need to read blob from the standard input

diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 3f115d9ca966879ccd7d587911d7d54bc88c08c2..c22916ddd91c8a2aee33b8a25f55def0c93b587b 100755 (executable)
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -77,7 +77,8 @@ test_expect_success 'submodule add' '
 
        (
                cd addtest &&
-               git submodule add "$submodurl" submod &&
+               git submodule add -q "$submodurl" submod >actual &&
+               test ! -s actual &&
                git submodule init
        ) &&
 
@@ -275,7 +276,8 @@ test_expect_success 'update should work when path is an empty dir' '
        echo "$rev1" >expect &&
 
        mkdir init &&
-       git submodule update &&
+       git submodule update -q >update.out &&
+       test ! -s update.out &&
 
        inspect init &&
        test_cmp expect head-sha1
@@ -448,6 +450,16 @@ test_expect_success 'add should fail when path is used by an existing directory'
        )
 '
 
+test_expect_success 'use superproject as upstream when path is relative and no url is set there' '
+       (
+               cd addtest &&
+               git submodule add ../repo relative &&
+               test "$(git config -f .gitmodules submodule.relative.url)" = ../repo &&
+               git submodule sync relative &&
+               test "$(git config submodule.relative.url)" = "$submodurl/repo"
+       )
+'
+
 test_expect_success 'set up for relative path tests' '
        mkdir reltest &&
        (