Merge branch 'bc/submodule-force-same-hash'

Adding a repository that uses a different hash function is a no-no,
but "git submodule add" did nt prevent it, which has been corrected.

* bc/submodule-force-same-hash:
  read-cache: drop submodule check from add_to_cache()
  object-file: disallow adding submodules of different hash algo

1 files changed, 25 insertions, 0 deletions

diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index fd3e7e355e..e6b551daad 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -407,6 +407,31 @@ test_expect_success 'submodule add in subdirectory with relative path should fai
 	test_grep toplevel output.err
 '
 
+test_expect_success 'submodule add of a different algorithm fails' '
+	git init --object-format=sha256 sha256 &&
+	(
+		cd sha256 &&
+		test_commit abc &&
+		git init --object-format=sha1 submodule &&
+		test_commit -C submodule def &&
+		test_must_fail git submodule add "$submodurl" submodule 2>err &&
+		test_grep "cannot add a submodule of a different hash algorithm" err &&
+		git ls-files --stage >entries &&
+		test_grep ! ^160000 entries
+	) &&
+	git init --object-format=sha1 sha1 &&
+	(
+		cd sha1 &&
+		test_commit abc &&
+		git init --object-format=sha256 submodule &&
+		test_commit -C submodule def &&
+		test_must_fail git submodule add "$submodurl" submodule 2>err &&
+		test_grep "cannot add a submodule of a different hash algorithm" err &&
+		git ls-files --stage >entries &&
+		test_grep ! ^160000 entries
+	)
+'
+
 test_expect_success 'setup - add an example entry to .gitmodules' '
 	git config --file=.gitmodules submodule.example.url git://example.com/init.git
 '