1 files changed, 66 insertions, 0 deletions
diff --git a/t/t7408-submodule-reference.sh b/t/t7408-submodule-reference.sh
index 1c1e289ffd..e159fc5035 100755
--- a/t/t7408-submodule-reference.sh
+++ b/t/t7408-submodule-reference.sh
@@ -125,4 +125,70 @@ test_expect_success 'ignoring missing submodule alternates passes clone and subm
 	)
 '
 
+test_expect_success 'preparing second superproject with a nested submodule plus partial clone' '
+	test_create_repo supersuper &&
+	(
+		cd supersuper &&
+		echo "I am super super." >file &&
+		git add file &&
+		git commit -m B-super-super-initial
+		git submodule add "file://$base_dir/super" subwithsub &&
+		git commit -m B-super-super-added &&
+		git submodule update --init --recursive &&
+		git repack -ad
+	) &&
+	git clone supersuper supersuper2 &&
+	(
+		cd supersuper2 &&
+		git submodule update --init
+	)
+'
+
+# At this point there are three root-level positories: A, B, super and super2
+
+test_expect_success 'nested submodule alternate in works and is actually used' '
+	test_when_finished "rm -rf supersuper-clone" &&
+	git clone --recursive --reference supersuper supersuper supersuper-clone &&
+	(
+		cd supersuper-clone &&
+		# test superproject has alternates setup correctly
+		test_alternate_is_used .git/objects/info/alternates . &&
+		# immediate submodule has alternate:
+		test_alternate_is_used .git/modules/subwithsub/objects/info/alternates subwithsub &&
+		# nested submodule also has alternate:
+		test_alternate_is_used .git/modules/subwithsub/modules/sub/objects/info/alternates subwithsub/sub
+	)
+'
+
+check_that_two_of_three_alternates_are_used() {
+	test_alternate_is_used .git/objects/info/alternates . &&
+	# immediate submodule has alternate:
+	test_alternate_is_used .git/modules/subwithsub/objects/info/alternates subwithsub &&
+	# but nested submodule has no alternate:
+	test_must_fail test_alternate_is_used .git/modules/subwithsub/modules/sub/objects/info/alternates subwithsub/sub
+}
+
+
+test_expect_success 'missing nested submodule alternate fails clone and submodule update' '
+	test_when_finished "rm -rf supersuper-clone" &&
+	test_must_fail git clone --recursive --reference supersuper2 supersuper2 supersuper-clone &&
+	(
+		cd supersuper-clone &&
+		check_that_two_of_three_alternates_are_used &&
+		# update of the submodule fails
+		test_must_fail git submodule update --init --recursive
+	)
+'
+
+test_expect_success 'missing nested submodule alternate in --reference-if-able mode' '
+	test_when_finished "rm -rf supersuper-clone" &&
+	git clone --recursive --reference-if-able supersuper2 supersuper2 supersuper-clone &&
+	(
+		cd supersuper-clone &&
+		check_that_two_of_three_alternates_are_used &&
+		# update of the submodule succeeds
+		git submodule update --init --recursive
+	)
+'
+
 test_done