Merge branch 'maint'

* maint:
  t4013: test diff-tree's --stdin commit formatting
  diff-tree: avoid lookup_unknown_object
  object_as_type: set commit index
  alloc: factor out commit index
  add object_as_type helper for casting objects
  parse_object_buffer: do not set object type
  move setting of object->type to alloc_* functions
  alloc: write out allocator definitions
  alloc.c: remove the alloc_raw_commit_node() function

t/t4013-diff-various.sh

@@ -324,4 +324,14 @@ test_expect_success 'diff --cached -- file on unborn branch' '
 	test_cmp "$TEST_DIRECTORY/t4013/diff.diff_--cached_--_file0" result
 '
 
+test_expect_success 'diff-tree --stdin with log formatting' '
+	cat >expect <<-\EOF &&
+	Side
+	Third
+	Second
+	EOF
+	git rev-list master | git diff-tree --stdin --format=%s -s >actual &&
+	test_cmp expect actual
+'
+
 test_done