tests/test-empty-manifest-index.t

test-http-bad-server: move on test from bytes-count to pattern

This specific test case is now using the new "close when a pattern is seen"
approach compared to the more fragile "that many bytes were sent" approach.

Since such change are still a bit noisy, we split each change in there own
changesets.

Differential Revision: https://phab.mercurial-scm.org/D12056

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]