tests/test-empty-manifest-index.t

resourceutil: force filesystem access to resources when using py2exe

I don't know why it doesn't work, but it avoids this fatal error on startup:

    > hg debugshell
    Traceback (most recent call last):
      File "hg", line 58, in <module>
      File "mercurial\dispatch.pyc", line 143, in run
      File "mercurial\dispatch.pyc", line 232, in dispatch
      File "mercurial\dispatch.pyc", line 254, in _rundispatch
      File "mercurial\ui.pyc", line 316, in load
      File "mercurial\rcutil.pyc", line 98, in rccomponents
      File "mercurial\rcutil.pyc", line 68, in default_rc_resources
      File "mercurial\utils\resourceutil.pyc", line 102, in contents
      File "<frozen zipimport>", line 775, in contents
    AssertionError

I assume the py2 version of py2exe never hit this because `importlib.resources`
failed to import.

Differential Revision: https://phab.mercurial-scm.org/D12554

Test null revisions (node 0000000000000000000000000000000000000000, aka rev -1)
in various circumstances.

Make an empty repo:

  $ hg init a
  $ cd a

  $ hg files -r 0000000000000000000000000000000000000000
  [1]
  $ hg files -r .
  [1]

Add an empty commit (this makes the changelog refer to a null manifest node):


  $ hg commit -m "init" --config ui.allowemptycommit=true

  $ hg files -r .
  [1]

Strip that empty commit (this makes the changelog file empty, as opposed to missing):

  $ hg --config 'extensions.strip=' strip . > /dev/null

  $ hg files -r .
  [1]