Merge branch 'master' into next

Merge branch 'master' into next

* master:
  t4013: test diff-tree's --stdin commit formatting
  t1402: check for refs ending with a dot
  Revert "Merge branch 'dt/refs-check-refname-component-sse'"
  Revert "Merge branch 'dt/refs-check-refname-component-sse-fix'"
  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