test_must_fail git notes list HEAD
'
+test_expect_success 'create note from non-blob with "git notes add -C" fails' '
+ commit=$(git rev-parse --verify HEAD) &&
+ tree=$(git rev-parse --verify HEAD:) &&
+ test_must_fail git notes add -C $commit &&
+ test_must_fail git notes add -C $tree &&
+ test_must_fail git notes list HEAD
+'
+
+cat > expect << EOF
+commit 80d796defacd5db327b7a4e50099663902fbdc5c
+Author: A U Thor <author@example.com>
+Date: Thu Apr 7 15:20:13 2005 -0700
+
+ 8th
+
+Notes (other):
+ This is a blob object
+EOF
+
+test_expect_success 'create note from blob with "git notes add -C" reuses blob id' '
+ blob=$(echo "This is a blob object" | git hash-object -w --stdin) &&
+ git notes add -C $blob &&
+ git log -1 > actual &&
+ test_cmp expect actual &&
+ test "$(git notes list HEAD)" = "$blob"
+'
+
cat > expect << EOF
commit 016e982bad97eacdbda0fcbd7ce5b0ba87c81f1b
Author: A U Thor <author@example.com>