Because git log --graph implies "--topo-order" and I didn't want that:

  $ git help log
  --graph
    [...]
    This implies the --topo-order option by default

Without "--date-order" it looks like this:

  $ git log --graph --all --decorate  --oneline
  * 86d911ec0f (HEAD -> master, origin/master, origin/HEAD) Allow index AMs to...
  * 7c5d8c16e1 Add explicit ORDER BY to a few tests that exercise hash-join code.
  * 8f93bd8512 Fix roundoff problems in float8_timestamptz() and make_interval().
  * a507b86900 Add WAL consistency checking facility.
  * 115cb31597 Fix relcache leaks in get_object_address_publication_rel()
  * e35bbea7dd doc: Some improvements in CREATE SUBSCRIPTION ref page
  * c3c4f6e174 Revise the way the element allocator for a simplehash is specified.

And 960 more commits before finally getting to this one... :-)

  | * 1888fad440 (origin/REL9_4_STABLE)