submodule: add absorb-git-dir function

diff --git a/t/t5526-fetch-submodules.sh b/t/t5526-fetch-submodules.sh
index 954d0e43f52375b1ed86a4edb9d274714d3b596d..f3b0a8d30afcb472398bef8623a49ba6bac7dc24 100755 (executable)
--- a/t/t5526-fetch-submodules.sh
+++ b/t/t5526-fetch-submodules.sh
@@ -485,4 +485,39 @@ test_expect_success 'fetching submodules respects parallel settings' '
        )
 '
 
+test_expect_success 'fetching submodule into a broken repository' '
+       # Prepare src and src/sub nested in it
+       git init src &&
+       (
+               cd src &&
+               git init sub &&
+               git -C sub commit --allow-empty -m "initial in sub" &&
+               git submodule add -- ./sub sub &&
+               git commit -m "initial in top"
+       ) &&
+
+       # Clone the old-fashoned way
+       git clone src dst &&
+       git -C dst clone ../src/sub sub &&
+
+       # Make sure that old-fashoned layout is still supported
+       git -C dst status &&
+
+       # "diff" would find no change
+       git -C dst diff --exit-code &&
+
+       # Recursive-fetch works fine
+       git -C dst fetch --recurse-submodules &&
+
+       # Break the receiving submodule
+       rm -f dst/sub/.git/HEAD &&
+
+       # NOTE: without the fix the following tests will recurse forever!
+       # They should terminate with an error.
+
+       test_must_fail git -C dst status &&
+       test_must_fail git -C dst diff &&
+       test_must_fail git -C dst fetch --recurse-submodules
+'
+
 test_done