tests/test-push-checkheads-partial-C2.t

revlog: fix resolution of revlog version 0

This partially backs out cecf3f8bccd3, "revlog: always process opener options."

My understanding is that if there's no "revlog1" nor "revlog2" in .hg/requires,
the repository should stick to the v0 format. The reasoning is briefly
described in 31a5973fcf96, "revlog: get rid of defversion."

Maybe we can drop support for missing opener options, but I didn't do that
in this patch.

====================================
Testing head checking code: Case C-2
====================================

Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.

This case is part of a series of tests checking this behavior.

Category C: case were the branch is only partially obsoleted
TestCase 2: 2 changeset branch, only the base is rewritten

.. old-state:
..
.. * 2 changeset branch
..
.. new-state:
..
.. * 1 new changesets branches superceeding only the base of the old one
.. * The old branch is still alive (base is obsolete, head is alive)
..
.. expected-result:
..
.. * push denied
..
.. graph-summary:
..
..   B ○
..     |
..   A ø⇠◔ A'
..     |/
..     ●

  $ . $TESTDIR/testlib/push-checkheads-util.sh

Test setup
----------

  $ mkdir C2
  $ cd C2
  $ setuprepos
  creating basic server and client repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd server
  $ mkcommit B0
  $ cd ../client
  $ hg pull
  pulling from $TESTTMP/C2/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets d73caddc5533 (1 drafts)
  (run 'hg update' to get a working copy)
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkcommit A1
  created new head
  $ hg debugobsolete `getid "desc(A0)" ` `getid "desc(A1)"`
  obsoleted 1 changesets
  1 new orphan changesets
  $ hg log -G --hidden
  @  f6082bc4ffef (draft): A1
  |
  | *  d73caddc5533 (draft): B0
  | |
  | x  8aaa48160adc (draft): A0
  |/
  o  1e4be0697311 (public): root
  

Actual testing
--------------

  $ hg push --rev 'desc(A1)'
  pushing to $TESTTMP/C2/server
  searching for changes
  abort: push creates new remote head f6082bc4ffef!
  (merge or see 'hg help push' for details about pushing new heads)
  [255]

  $ cd ../..