=========================================
Testing single head enforcement: Case A-2
=========================================

A repository is set to only accept a single head per name (typically named
branch). However, obsolete changesets can make this enforcement more
complicated, because they can be kept visible by other changeset on other
branch.

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

Category A: Involving obsolescence
TestCase 2: A branch is split in two, effectively creating two heads

.. old-state:
..
.. * 2 changeset changeset on branch default
.. * 2 changeset changeset on branch Z on top of them.
..
.. new-state:
..
.. * 2 changeset changeset on branch Z at the same location
.. * 1 changeset changeset on branch default unchanged
.. * 1 changeset changeset on branch default superceeding the other ones
..
.. expected-result:
..
.. * two heads detected
..
.. graph-summary:
..
..   D ●      (branch Z)
..     |
..   C ●      (branch Z)
..     |
..   B ø⇠◔ B'
..     | |
..   A ● |
..     |/
..     ●

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

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

  $ mkdir A2
  $ cd A2
  $ setuprepos single-head
  creating basic server and client repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd client
  $ mkcommit B0
  $ hg branch Z
  marked working directory as branch Z
  (branches are permanent and global, did you want a bookmark?)
  $ mkcommit C0
  $ mkcommit D0
  $ hg push --new-branch
  pushing to $TESTTMP/A2/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files
  $ hg up 0
  0 files updated, 0 files merged, 4 files removed, 0 files unresolved
  $ mkcommit B1
  created new head
  (consider using topic for lightweight branches. See 'hg help topic')
  $ hg debugobsolete `getid "desc(B0)" ` `getid "desc(B1)"`
  1 new obsolescence markers
  obsoleted 1 changesets
  2 new orphan changesets
  $ hg log -G --hidden
  @  25c56d33e4c4 [default] (draft): B1
  |
  | *  cdf1dbb37a67 [Z] (draft): D0
  | |
  | *  3213e3e16c67 [Z] (draft): C0
  | |
  | x  d73caddc5533 [default] (draft): B0
  | |
  | o  8aaa48160adc [default] (draft): A0
  |/
  o  1e4be0697311 [default] (public): root
  

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

(force push to make sure we get the changeset on the remote)

  $ hg push -r 'desc("B1")' --force
  pushing to $TESTTMP/A2/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  transaction abort!
  rollback completed
  abort: rejecting multiple heads on branch "default"
  (2 heads: 8aaa48160adc 25c56d33e4c4)
  [255]