builtin/submodule--helper: factor out submodule updating

diff --git a/t/t7410-submodule-checkout-to.sh b/t/t7410-submodule-checkout-to.sh
index 3f609e8909c463e7d396915d273d82785b238000..1acef32647aee6ef33638fd35be4d3e3ad61c726 100755 (executable)
--- a/t/t7410-submodule-checkout-to.sh
+++ b/t/t7410-submodule-checkout-to.sh
@@ -47,4 +47,14 @@ test_expect_success 'checkout main and initialize independed clones' \
 test_expect_success 'can see submodule diffs after independed cloning' \
     '(cd fully_cloned_submodule/main && git diff --submodule master"^!" | grep "file1 updated")'
 
+test_expect_success 'checkout sub manually' \
+    'mkdir linked_submodule &&
+    (cd clone/main &&
+       git worktree add "$base_path/linked_submodule/main" "$rev1_hash_main") &&
+    (cd clone/main/sub &&
+       git worktree add "$base_path/linked_submodule/main/sub" "$rev1_hash_sub")'
+
+test_expect_success 'can see submodule diffs after manual checkout of linked submodule' \
+    '(cd linked_submodule/main && git diff --submodule master"^!" | grep "file1 updated")'
+
 test_done