tests/test-push-checkheads-unpushed-D1.t

context: stop catching RepoLookupError from namespace.singlenode()

As pointed out by Yuya, the RepoLookupError was there for catching
errors from repo.branchtip(). However, since 885c0290f7d5 (localrepo:
add ignoremissing parameter to branchtip, 2014-10-16), that should no
longer happen. I think it should now be an error if a namespace raises
a RepoLookupError, so we propagate the exception up and and make it
easy to fix, rather than trying to interpret the changeid as nodeid
prefix and raise a general "unknown revision '...'" error.

I also don't think we should catch FilteredLookupError and LookupError
from the changelog.rev() call, for the same reason as above: If a
namespace returns a node that doesn't exist, we should provide a more
helpful exception than "unknown revision '...'".

Differential Revision: https://phab.mercurial-scm.org/D3145

====================================
Testing head checking code: Case D-1
====================================

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 head is rewritten, but successors is not part of the push

.. old-state:
..
.. * 1 changeset branch
..
.. new-state:
..
.. * 1 changeset branch succeeding the old branch
.. * 1 new unrelated branch
..
.. expected-result:
..
.. * pushing only the unrelated branch: denied
..
.. graph-summary:
..
..   A ø⇠○ A'
..     |/
..     | ◔ B
..     |/
..     ●

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

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

  $ mkdir D1
  $ cd D1
  $ setuprepos
  creating basic server and client repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd client
  $ 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
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkcommit B0
  created new head
  $ hg log -G --hidden
  @  74ff5441d343 (draft): B0
  |
  | o  f6082bc4ffef (draft): A1
  |/
  | x  8aaa48160adc (draft): A0
  |/
  o  1e4be0697311 (public): root
  

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

  $ hg push -r 'desc(B0)'
  pushing to $TESTTMP/D1/server
  searching for changes
  abort: push creates new remote head 74ff5441d343!
  (merge or see 'hg help push' for details about pushing new heads)
  [255]

  $ cd ../..