tests/test-push-checkheads-unpushed-D2.t

wireproto: client reactor support for receiving frames

We can now feed received frames into the client reactor and it will
validate their sanity, dispatch them appropriately.

The hacky HTTP peer has been updated to use the new code. No
existing tests changed, somewhat proving the code works as
expected.

Rudimentary unit tests for the new functionality have been
implemented.

Differential Revision: https://phab.mercurial-scm.org/D3224

====================================
Testing head checking code: Case D-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 D: remote head is "obs-affected" locally, but result is not part of the push
TestCase 1: remote branch has 2 changes, head is pruned, other is rewritten but result is not pushed

.. old-state:
..
.. * 1 changeset branch
..
.. new-state:
..
.. * old head is pruned
.. * 1 new branch succeeding to the other changeset in the old branch
.. * 1 new unrelated branch
..
.. expected-result:
..
.. * push allowed
.. * pushing only the unrelated branch: denied
..
.. graph-summary:
..
..   B ⊗
..     |
..   A ø⇠○ A'
..     |/
..     | ◔ C
..     |/
..     ●

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

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

  $ mkdir D2
  $ cd D2
  $ 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/D2/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets d73caddc5533
  (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 debugobsolete --record-parents `getid "desc(B0)"`
  obsoleted 1 changesets
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkcommit C0
  created new head
  $ hg log -G --hidden
  @  0f88766e02d6 (draft): C0
  |
  | o  f6082bc4ffef (draft): A1
  |/
  | x  d73caddc5533 (draft): B0
  | |
  | x  8aaa48160adc (draft): A0
  |/
  o  1e4be0697311 (public): root
  

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

  $ hg push --rev 'desc(C0)'
  pushing to $TESTTMP/D2/server
  searching for changes
  abort: push creates new remote head 0f88766e02d6!
  (merge or see 'hg help push' for details about pushing new heads)
  [255]

  $ cd ../..