difftool --no-index: error out on --dir-diff (and don't crash)

diff --git a/t/t5572-pull-submodule.sh b/t/t5572-pull-submodule.sh
index 321bd37deb3d32027c18f8184a9ad46aec9c96c7..f916729a12b24b75184144c2eaa9abdbf1c12639 100755 (executable)
--- a/t/t5572-pull-submodule.sh
+++ b/t/t5572-pull-submodule.sh
@@ -132,4 +132,25 @@ test_expect_success 'pull rebase recursing fails with conflicts' '
        test_i18ngrep "locally recorded submodule modifications" err
 '
 
+test_expect_success 'branch has no merge base with remote-tracking counterpart' '
+       rm -rf parent child &&
+
+       test_create_repo a-submodule &&
+       test_commit -C a-submodule foo &&
+
+       test_create_repo parent &&
+       git -C parent submodule add "$(pwd)/a-submodule" &&
+       git -C parent commit -m foo &&
+
+       git clone parent child &&
+
+       # Reset master so that it has no merge base with
+       # refs/remotes/origin/master.
+       OTHER=$(git -C child commit-tree -m bar \
+               $(git -C child rev-parse HEAD^{tree})) &&
+       git -C child reset --hard "$OTHER" &&
+
+       git -C child pull --recurse-submodules --rebase
+'
+
 test_done